fish

Guide to responsible spearfishing #3

So far in this series we have looked at where your can spear and what you can spear. Next up we’re going to take a look at what gear you’re going to need to go spearfishing.

What gear should I buy?

Be prepared to spend a bit of money on your gear. Cheap gear is cheap for a reason. Talk to some locals or get onto some forums and see what other people are using and saying about their equipment. If possible, try to borrow some gear before you invest in your own kit. Most experienced spearo’s will have spare gear laying around. Talk to them and see what they liked/didn’t like about that gear. You can build up to better gear to some extent, but there are some basics that you will need to get started.

Mask and snorkel

If you’re considering getting into spearfishing, you’ve probably done some snorkelling or diving. It’s fine to use a mask and snorkel that you’ve bought for this purpose however there are a few things you may want to consider for a spearfishing mask when it comes to upgrading or buying your first one. Firstly, a black (or any non-clear colour) silicone skirt. This will stop reflections on your mask lens and enable you to spot fish better from the surface. It sounds like a minor annoyance, but it’s one of those little things that can make a big difference. Second, you want a low volume mask. A low volume mask requires less air to equalise at depth and will sit closer to your eyes giving you a better field of vision. lastly and by far the least important are mirrored or shaded lenses. These are totally non-essential, but fish will tend to come in closer when they can’t see you looking at them. I have always owned masks with clear lenses but it means that I track fish in my peripheral vision and only look directly at them when I’m ready to shoot.

Comparison of freediving (left) and scuba diving (right) masks

Snorkels – In my experience, it doesn’t really matter. Try to avoid those big splash guards on the top as they tend to make the snorkel flop around. Learn to use your tongue as a splash guard instead. A stiff snorkel is better for spearing as it won’t flop around as much. Also, don’t rely on those plastic clips to attach the snorkel to your mask. Get one of the old-school silicone ones or simply slip the snorkel under your mask strap.

Fins

Comparison of diving (top) and freediving (bottom) fins. Note: the split in the diving fin is not appropriate for spearfishing.

You can use pretty much anything to get you started but you will probably want to upgrade as soon as you can. Good fins will make a big difference in your breath holding ability. That being said, I know people who use body board fins for spearfishing. Proper freediving fins are much more energy efficient which is why a good pair will help a lot with your breath hold and you’ll be able to chase faster fish with them too. The down side is that a decent set are going to cost you. split-fins, often used for scuba diving are not so great for spearfishing. They are ok in terms of speed and energy, however your float line can get very easily tangled between the blades. For that reason, I really would not recommend this style of fin. Full foot or strap? I prefer full foot for spearfishing as it means less neoprene around my feet – you use a thin sock rather than wetsuit booties. However some rock hoppers might prefer something more solid on their feet for getting to their dive sites.

Wetsuit

Again, pretty much any wetsuit will be fine to get you started as long as it’s an appropriate thickness for the water temperature where you dive. When you decide it’s time to invest in a good wetsuit, there are a couple of things to consider. Firstly, 1-piece or 2-piece? Most spearfishing wetsuits are 2-piece. I don’t really know why. I did use my 1-piece scuba diving wetsuit for spearfishing for years before upgrading so I don’t think there is any real issue there. Just good to know that both types exist. Secondly, open or closed cell neoprene? Most spearo’s I know like the open cell wetties because they’re warmer and allow for a greater range of movement. However, they are harder to get into (you’ll need to lube yourself up) and they are less durable than their closed cell counterparts. Next, think about the colour. I used to laugh at people in camo wetsuits until I saw one in action. I watched my buddy almost disappear into a bed of kelp. Now I wear a camo wetsuit. Whether you like camouflage or not, darker colours are better, but at the end of the day, get something that is comfortable for you and suitable for the area you dive.

Gloves

Quite possibly the most contentious issue in spearfishing! At the end of the day, gloves aren’t going to cost you an arm and a leg so try a few and find a pair that work for you. But you will need a pair of gloves. Some fish are very spiky so gloves will help to prevent a painful encounter. Also you’ll most likely be around rocky reefs or some kind of hard substrate so gloves will mitigate scrapes and cuts and make entries and exits from a rocky shore much less painful.

Weightbelt

Anything will get the job done here, but most spearo’s prefer the rubber type as they don’t slide around as much. Some people like a crotch strap to keep it in place. Other people love weight vests as you can distribute the weights evenly around your body. A downside to vests is that they may not ditch as easily in an emergency. Be sure to position your weights toward the back so that if you pass out, your weight belt will roll you onto your back. Never overweight yourself! If you’re negatively buoyant at the surface, you’re wearing too much weight. You should be able to float with your collarbone above water when you position yourself vertically and take a breath in. It’s worth taking that extra bit of time to get your weights set up correctly before you head out into deeper water.

Spear or Speargun

Hand spears

Some people love them. Most people start out with them. Some people I know tow one behind their float for flathead or fish inside caves. Honsetly, I can’t tell you much about these as I haven’t used one for a really long time. Basically you can buy them with aluminium or fibreglass shafts. They are cheaper than a speargun and you will catch some fish using them. However, they have less range and in my limited experience tend to be less accurate, though that probably comes down to the user.

Spearguns

Spend some money here and get something decent. Do some research and find out the pro’s and con’s of each brand and each model. A cheap gun will be less accurate and won’t last you very long. They are also quite inconsistent in their aim which makes it very difficult for a beginner to develop that skill – what worked last time may not work next time. Look for a gun with rails to guide the spear.

Size matters, but bigger is not always better. Long guns will give you longer range (generally) and tend to have more ‘punch’. Shorter guns are easier to track side to side. Have a think about what kind of fish you want to target. Long guns are generally better for bigger pelagics whereas shorter guns tend to be better for reef fish darting in and out of the rocks. Shorter guns are generally easier to load. Don’t agonize too much over length though. You’ll probably go through a few until you find a size that suits your style. 100 to 110 cm guns are probably a good starting point. I have used a 120 cm gun around rocky reefs to great effect and I’ve brought in some good sized kingfish on a little 90 cm.

Single or double rubbers? It comes down to what you’re targeting. I find a single rubber suits me for most of my fishing, however my gun can accommodate a second. I like this configuration because it allows me to attach a second rubber to my gun as a spare in case one of them breaks. Having both rubbers loaded won’t give you a longer range, but it will give the spear more ‘punch’ and the spear will reach your target quicker so the second rubber can be good for targeting faster moving species.

Reels or wrapped line? Never used a reel so I can’t really comment. A reel won’t increase your range. The spear will lose momentum well before it reaches the end of a wrapped shooting line. However if you’re wanting to shoot bigger fish, a reel will probably help you land it. Comments on reels welcome! Bungee or no bungee? Doesn’t really matter. A bungee is a small piece of rubber attached between the shooting line and the muzzle. I like them because it makes reloading the shooting line easier. More importantly it dampens the movement of a struggling fish meaning less tear-offs while you’re landing a fish.

Open or closed muzzle? Open muzzles allow you to aim down the full length of the spear and make reloading the spear a bit quicker as you don’t need to thread the spear through the hole in the muzzle. The line wrap is a little more complicated though as the shooting line is used to hold the spear to the barrel. The shooting line which holds down the spear on an open muzzle may come loose in rough conditions and you need to be spot on with the length of the shooting line when you replace it. You can’t use a bungee on an open muzzled gun. Closed muzzles may take a little longer to reload, but I’ve never really considered this to be a big problem on my closed muzzle guns. While you can’t see down the full length of the spear for aiming with a closed muzzle, you do get used to it and I certainly haven’t had any issues with accuracy using a closed muzzle.

Roller guns are becoming popular and are worth a mention. I have never used one so would love to hear from anyone who has. The idea of these guns is that the length of the barrel can be reduced while still facilitating a longer rubber, giving more power with the advantages of a shorter gun. The spear also gets a straighter pull from the rubbers and hence greater accuracy. They seem a little more complicated to reload and maintain, but certainly nothing that couldn’t be learned from a YouTube tutorial.

A note on safety

Never ever point your spear or speargun at another person. In fact, don’t even point it at a fish unless you’re going to shoot it. Treat it like a firearm. Even though most spearguns come with a safety catch, there is no guarantee that it will hold. These things are not toys. They are killing implements. Treat them with respect.

Float and line

Yes you need these! Anyone who’s ever driven a boat knows how difficult it can be to spot a person in the water. For this reason your float should be a bright colour and stand out (unlike your wetsuit). Get a float that comes with a flag, preferably on a giant pole sticking way above the water. You may need to add a ballast weight to the bottom of your float to stop it rolling flag-side down. Streamlined floats are easier to tow, however I started out with a couple of spray painted milk bottles. Not ideal, but they got me started.

My float is probably my favourite bit of gear. It’s a great place to store a bunch of things. I keep an abalone knife and a mesh bag on mine as well as a photocopy of my fishing licence in a waterproof bag. One of the requirements in NSW is that you must carry your licence with you when you’re fishing. Obviously you don’t want to take your wallet with you into the water, so a lot of people just write their licence number on their float. This should satisfy most reasonable fisheries officers. Make sure you have your actual fishing licence in your car though.

You can use pretty much any kind of synthetic rope for your float line. It should be appropriate for the depth you want to dive to. Too much line will get tangled and your float will probably be up on the shore. Too little line and you won’t be able to get the bottom. You need buoyant rope. If your line sinks, you’ll spend all of your time trying to untangle it from rocks and weed. Your line also needs to be thin enough to thread your fish onto but not so thin that it breaks off in the swell. Five to eight millimeters is a good diameter. One end of the line should be attached to your gun and the other end to your float. Most people I know string their fish on their float line. You can get a neat bit of gear called a speed spike which allows you to thread your fish (through the gill slit and out the mouth) onto your line more easily. I highly recommend getting one of these.

Knife

Spearfishing knives (left and middle) vs diving knife (right). The Mac Sub 11D is on the left.

You need a knife for spearfishing. Firstly to kill your fish (if you don’t kill it outright) and secondly in case of entaglement. Remember, you will be towing a float and there is the potential for an entanglement. For that reason your knife needs to be in an accessible location on your body. I don’t like knives on the leg. I know you think it looks cool with a big dagger strapped to your calf, but it is more difficult to get to. A lot of spearo’s strap their knife to their forearm or upper arm. Personally I like mine on my belt. Get a knife with a slender blade and a fine point. This is what you will use to kill the fish. Typical scuba diving knives have a broader blade and these can work for spearfishing but they’re not great. The Mac Sub 11D is a great starting point that won’t break the budget.

Summary

Well, I think that just about covers all of the gear that you will need to get you started. I may do another post on ‘nice-to-have’ gear later on. I know that it’s very tempting to look for the cheapest gear you can find when starting out and that is ok in some areas. but I think you can save yourself some money in the long run if you invest in decent gear. The speargun and fins are probably the two areas that it’s really worth spending the extra cash.

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Guide to responsible spearfishing #2

So, you’ve sussed out a nice easy dive site that isn’t in a no-fishing zone and looks like it could hold some fish.

In my last post I covered the rules and regulations around where you can/can’t spearfish. Next up in this series is a little bit about what fish to catch. The number one take away message from this post is: If you don’t recognise it, DON’T shoot it! 

What fish can I catch?

There is NO catch and release with spearfishing. If you spear a fish, it is most likely going to die. I have seen fish swimming around with spearfishing injuries, but these fish can’t swim as well as healthy fish and are more likely to suffer mortality through predation or reduced fitness. So, if you’re going to pull that trigger, make sure that your spear is pointing at something you are going to eat and be damn sure that it’s not a protected species – heavy fines apply. If you don’t recognise it, DON’T shoot it! 

The NSW DPI website has all the details of fish you are allowed to spear and their bag and size limits. Fisheries authorities in other states and countries should have a similar resource. It has pictures. Learn these species and their bag and size limits. No short-cuts here. Spend some time on this page. If a species doesn’t appear on this list, it probably isn’t regulated, but it’s also probably not fished very often, usually because it doesn’t taste very good. There are a lot of fish to learn on this list so my advice would be to pick a species that you know is abundant in your area, memorise the bag and size limits for it and only target that one species when you go spearfishing for your first time. Pick another species to memorize on your next outing and soon you will have a long list of species that you can quote the bag and size limits off the top of your head. Again, there really is no substitute for having someone experienced show you what is ok and what is not. If you don’t recognise it, DON’T shoot it! 

There are a number of good fish identification books available and I would recommend getting very familiar with these. Below are a few of my favourites. A great online resource if you can take photos is inaturalist.org. Make a profile and post some pictures asking for advice and you will find a very helpful and knowledgeable community to help you ID that fish. It will be difficult at first to tell a lot of fish apart, but you will get better at it the more time you spend in the water. If you don’t recognise it, DON’T shoot it! 

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You will learn to identify fish a lot faster if you take an active interest in it. When you’re next out in the water and see something you don’t recognise, try to memorise as much detail (or take a photo if you have a camera) and go searching for it when you get home. You’d be surprised how often google hits the mark when you search for “fish with yellow stripes”. Markings are not the only thing to look for. Look at shapes. This will often help you to identify families of fishes. Fishes in the same family often (but not always) taste similar. Look for where the fish is found – bottom dwelling, surface swimming, mid water. Look for behaviours. For example, a fish sculling with its pectoral fins is probably a wrasse. Knowledge of all of these aspects will help you to recognise fish species from a distance and in low vis and will definitely help you to avoid a nasty fine. If you don’t recognise it, DON’T shoot it!

 

What fish can’t I catch?

There are a number of protected species and unfortunately these protections can vary from state to state. On top of this there are also Commonwealth protected species so you need to check a couple of places. For Commonwealth protected species check out this page. It’s not the easiest page to navigate, but if you find a species on here it will have a lot of information and links to pictures of it. For NSW protected species look no further than the NSW DPI page. It is worth getting to know the protected species living in your area as interfering with these species can result in massive fines. A few special mentions for southern NSW are below.

Blue groper

Blue wrasse aka blue groper are off limits to spearo’s. This is because they are a naturally inquisitive fish and will swim right up to a diver to check them out. For this reason, a lot of newbies get caught out and get excited about the great big fish right at the end of their spear. DO NOT shoot these fish. Be aware that the female blue gropers (they change sex to male when the dominant male in the area dies) are brown or yellow in colour. Learn to identify this species and do not shoot them. You can have a lot of fun when these fish are around. They will hang around and check you out. Try tapping your knife on a rock – they will often swim in very close to you to see what you’re doing. Some people like to cut up sea urchins for the gropers but I advise against this practice. These fish are very capable of feeding themselves and cutting up urchins is an unnecessary waste of life.

Blue drummer

Blue Drummer

Black Drummer

This is an interesting one and not a species that I was aware of until recently. Not usually sighted in southern NSW, but there was a recent report of one so worth knowing about. I’ve included it here because it could be easily confused with the black drummer, which you can spear and which is really good eating. They (the black drummer) are fairly long lived though so make sure there is a healthy population before taking one. Info on the blue drummer can be found here.

What fish should I catch?

 Some good sustainable species for beginners

Most nearshore species are quite abundant and good for cutting your teeth on. They are also excellent eating. Some species that I recommend are luderick, bream and tarwhine. These species may take some practice as they spook easily and can move really fast. But they are often found up in the shallows which makes them good species to target while you’re learning to increase your breath hold. Red morwong are also often targeted by beginners because they don’t move much. It’s ok to target these on your first few outings, but try to move on to other species as soon as you can as morwongs are relatively long lived species. I include them here because fishing pressure is generally low and they are fairly abundant on most reefs.

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Some more challenging species

Once you gain some confidence, it’s a good idea to try for some of the faster, more challenging species. The good news is that these species taste great and the challenge makes them really exciting to catch. Most of these species are fast growing and highly fecund (good breeders) so are more sustainable than the slower growing fish.

Australian Salmon

Australian Salmon gather in large schools and will sometimes cruise past. They are more common in the winter months in NSW. The challenging part to catching one of these fish is that they are quick and the schooling behaviour makes it difficult to target a single individual. Good aim is a must on these fish as the flesh is very soft and a body shot often results in the fish tearing off your spear and slow a agonizing death. Head-shots are best for most species, but Salmon especially. Bigger is NOT better with salmon. The big ones are quite dry so aim for fish around the 30 – 50 cm mark.

Bonito

Bonito also gather in schools but are sometimes seen as solitary individuals. Bonito is one of my favourites. Dive bombing works well, but you have to be able to keep pace until the bonito turns to be able to take a shot. A good breath-hold is needed to chase one down.

Trevally

Trevally are also great eating. While not as fast as the salmon and bonito they do spook easily and their schooling behaviour can make an individual difficult to target. Stealth is required to catch these fish.

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Invertebrates

You can catch lobsters with your hands but you must not use your speargun or any other tool to obtain them. Abalone, scallops, urchins and other shellfish are also fine to take by hand (you’ll probably want a knife for abalone) but you must still abide by the bag limits. Do not dispose of abalone guts in the water. This is to reduce the transmission of a disease that severely impacted the abalone fishery a few years ago. Process them at home and bin the guts. See the applicable closure notices here for the rules on abalone.

Tasty, but think twice

Flathead

Flatties are good eating but just be aware that all of the large ones are female so bigger is NOT always better. Also, don’t shoot directly down at them. You will bend your spear in the sand. There are techniques for damping the rubbers on your gun which you should learn.

Kingfish

Kingies are a real challenge and very tasty. They do get big and they are strong so be prepared for a fight. I have bent spears whilst landing Kingfish. I don’t target Kingfish very often any more. They do grow and breed quite quickly, but they also face very high fishing pressure from recreational and commercial fisheries.

Black Drummer

Black Drummer are fairly abundant on many reefs, but they are slow growers. I catch them every now and again, but I always make sure there are plenty around before deciding to target one. Also, make sure you can tell the difference between black and silver drummer. Silver drummer are yuk (in my opinion). They get massive and swim around in large schools. You will be tempted to take a shot on one, but I wouldn’t advise it. Black drummer can change their colour and can appear silver, especially when stressed. They don’t tend to get as big as the silvers, and usually hide among the boulders. Juveniles will school like silver drummer.

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Next Issue

Hopefully this post has given you an idea of where you can find information on fish species and some things to think about in terms of sustainability. Obviously there are dozens more species than those I have listed here. The species above are common on near-shore reefs in southern NSW. I would love to hear from you about what you target. The take home message is to do your research into the species in your local area before you hit the water and of course, if you don’t recognise it, DON’T shoot it!

Next up, I will take a look at the equipment you need to get out into the water.

Guide to responsible spearfishing #1

Spearfishing is a great way to connect with the ocean and to get some omega 3 into your diet. It is a sustainable method of fishing when done responsibly as you only take what you need and you can target the more sustainable species and sizes. Contrary to popular opinion, the average spearo doesn’t go out indiscriminately killing everything that moves. In fact I often come home with nothing. For me the pleasure comes from being in the ocean and learning about fishy behaviour. If I happen to catch a feed that’s great! but I’m just as happy to have been underwater, watching the aquatic world pass by. Last weekend I was lucky enough to swim with a pod of dolphins for a few minutes. The video below is worth a look and talks a bit about these motivations.

My impetus for writing this article comes from discussions I’ve been involved in recently regarding how difficult it is to find information on spearfishing rules and regulations. Additionally, the Christmas period is fast approaching which often brings on a spate of green spearo’s who’ve been given some brand new gear as a gift and are perhaps a little over-excited to go and catch a feed. While this excitement is understandable, I would like to see everyone enjoying this activity responsibly for many years to come.

I’ve been involved in spearfishing for many years now and I still find it difficult to find good information so I hope that this series of articles will help to bring the information together that you’ll need to get into this sport safely and responsibly. At the very least it should give you an idea of the authorities involved in regulating spearfishing activity. A lot of this will be aimed at people just starting out in spearfishing, but I hope that some of the resources will help experienced spearo’s to figure out where they can fish as well.

Before I get into it, I want to apologise for the bias toward NSW regulation in this article, but that is where I fish so it’s what I’m familiar with. Similar resources should be available from the equivalent Fisheries/land management authorities in your region.

Starting out

Spearfishing in Tonga. I’m using a homemade slingshot and the spear is the shaft from the hinge on an old chest freezer. The Tongans are a resourceful bunch!

There really is no substitute for tagging along with an experienced person. Someone who can guide you in safety and in what you can/can’t shoot. However, I realise that it’s not always possible to find someone willing to take you along. I suggest checking out some spearfishing forums and asking if anyone in your local area is happy for you to go along with them. My experience with these forums is that most people are supportive of helping out a newbie and are pretty happy to show you the ropes. But before you even get to this stage, you should do some reading – I hope the following article will provide a lot of necessary information for you. A little bit of prior knowledge will go along way toward showing an experienced buddy that you are serious about getting into this activity and that you care about the reputation of your fellow spearo’s.

Forums:
Adreno
Extreme spearfishing – Currently unavailable, but check out their facebook page

Before you get in the water

Get to know the rules for your local area. 10 minutes on google could save you a massive fine for being an idiot and spearing a protected species in a no-fishing zone. In NSW you must obtain a fishing licence. These are very easy to acquire, available at most fishing tackle shops or online here. Spearfishing is NOT allowed on scuba in NSW.

Where can I spearfish?

You’ll want to start out somewhere nice and protected. Have a look on google earth for places close to you. Identify somewhere that looks like it has good access for the time being. You’ll learn to identify good fishing areas as you progress, but for now, just find somewhere you can get in and out without too much difficulty. Headlands may offer some protection from wind and wave action depending on the direction of the wind and swell. Beaches are easy to enter and exit from, but you are only permitted to carry a spear within 20 m of the end of the beach.

An example of an easy site. Close to parking, beach entry/exit and plenty of rocky reef close by. Assuming north is toward the top of the pic, this site would get good protection from westerly winds.

In NSW, spearfishing is subject to all of the rules applying to saltwater fishers. The fisheries rules are in place in order to sustainably manage this shared resource. They may not be perfect, but take it from me, our fisheries in Australia are much healthier than regions where fisheries are unregulated. Visit the NSW DPI recreational fishing page for these rules and closures. There is NO spearfishing in freshwater in NSW. Ocean beaches (except 20 m from either end) are also off limits. A great resource for checking whether an area is closed to spearfishing is the NSW DPI Primefact available here. In addition to these closures there is a network of marine protected areas (MPAs) along the coast of NSW. MPAs consist of marine parks, aquatic reserves and special aggregation areas.

Marine parks

There are six marine parks in NSW. They have several types of zone. Usually you can fish in a general purpose (yellow) zone, but check the zoning map to make sure. There is NO fishing in red zones. Information and zoning maps are available here. There is signage at most access points to beaches within marine parks showing the zoning of the area.

Aquatic reserves

Aquatic reserves are a tricky bunch as each one differs in what you can/can’t do. Thankfully, the NSW DPI has consolidated all of this info for you and you can find out whether speafishing is allowed or not on this website.

Grey nurse shark aggregation sites

Photo Credit: Kylie Brown

Grey nurse sharks were hunted to near extinction in the 1960’s. It’s a black mark in spearfishing history, but thankfully the species is showing signs of recovery. There are several recognised grey nurse shark aggregation sites and like aquatic reserves, they vary in what you can and can’t do so make sure you check whether you can spearfish or not on this website.

A lot of scuba divers will talk about how harmless these sharks are and that’s pretty true. However be aware that these are large wild animals and you should treat them with respect. I know of at least one case of a spearo being bitten by a grey nurse shark, so just be aware. By all means, take a look if you see one – they are majestic animals, but be aware of their behaviour and take into consideration whether you are trailing dead fish on your float. Learn to recognise a pissed off shark (fast, erratic movements; pectoral fins pointed down; head arched back). They will let you know if they don’t want you around. Always give them an exit.

National parks

NSW national parks generally only manage activities on the land but there are some rules that may apply to you as a spearo accessing the water through a national park. National parks are tricky to find info about spearfishing. From what I can gather each park has its own plan of management and if that plan makes reference to spearfishing or spearguns you must comply with that. If the plan of management makes no reference to spearfishing or spearguns, then I think the regulation below applies. Plans of management are available here. The NSW National Parks and Wildlife Regulation 2009 contains the following:

National Parks and Wildlife Regulation 2009
Part 2 Division 3 Clause 20
20   Weapons
(1)  A person must not in a park:
(b)  carry or discharge or have in the person’s possession any airgun, speargun or other lethal weapon
(6)  A person does not commit an offence under subclause (1) (b) if the person carries or possesses an unloaded speargun in a park, unless a plan of management for a park or a notice erected in the park or given to the person prohibits the carrying or possession of a speargun (whether loaded or unloaded) in a park or any part of the park.
(8)  In this clause, unloaded speargun means:
(a)  an assembled rubber powered speargun that does not have the shaft engaged in the trigger mechanism and the rubbers stretched and engaged in the shaft, or
(b)  in the case of a pneumatic, spring or gas powered speargun—one that does not have the spear shaft located within the barrel of the speargun, or
   (c)  a disassembled speargun.

If you are going to be carrying your speargun through a national park, I would recommend calling the appropriate office and talking to the park manager. You shouldn’t have your gun loaded on land anyway, but ensure that it is unloaded at all times in the national park and disengage the spear shaft from the trigger mechanism. i.e. carry the spear shaft separately from the gun body.

Commonwealth National Parks

There are six Commonwealth National Parks in Australia. Kakadu NP is bordered by the sea to the north, though admittedly, I know absolutely nothing about spearfishing in the Northern Territory and I couldn’t find any reference to spearfishing on the Kakadu NP website. My advice would be to call the ranger station and ask about it if you plan on braving the crocs up there! Booderee National Park encompasses waters of Jervis Bay. Spearfishing is prohibited and spears or spear guns are not allowed in this parkNorfolk Island and Christmas Island National Parks also have oceanic boundaries and again, I could not find any reference to spearfishing on their respective websites. If you are lucky enough to be on one of these islands, then talk to the rangers to find out if you can spear there. The take home message here is that if you can’t find the information, talk to someone. Don’t just assume the it’s ok to go spearfishing. You could end up with a nasty fine or with your gear impounded.

Next Issue

So that pretty well sums up the rules and regulations around where your can spearfish or at least should give you some idea of where to find the information. I know it’s a lot, but you only have to check out your sites once and you will get to know your local area. In the next part of this guide I will cover what you can/can’t fish for. Remember, there is no catch and release in spearfishing. If you don’t know what it is, DON’T shoot it. I’ll cover where to find information on protected species and suggest some easy species to get started on and move on to some good sustainable fish species.

Into the Storm

slide1

Earlier this year I presented some of my findings at the 2016 Australasian Society for the Study of Animal Behaviour Conference in Katoomba. These findinges were based on data collected over the last 2 years during which my field sites have been impacted by 2 cyclones. Below is an adaptation of the talk from the conference.

The Importance of Sociality

slide2There are lots of examples in nature of animals that form social groups. These species gain advantages and incur disadvantages from their social behaviour. For example an advantage might be better predator detection while foraging (known as the “many eyes” hypothesis) while a disadvantage could include higher rates of disease transmission. Studies suggest that the evolution and maintenance of sociality is likely to be influenced by environmental factors. Changes in the environment, like those caused by extreme weather events, are therefore likely to impact upon the social organisation of social species.

For social species, the balance between the advantages and disadvantages of sociality are vitally important in determining reproductive output, competitive ability, foraging success and survival, factors which can ultimately impact on a species’ ability to recover from a major impact.

The Study System

slide3My research focuses on the coral gobies at Lizard Island, Queensland. Coral gobies are small fish, approximately three to four centimeters in length and they spend their entire adult lives within the branches Acroporid corals (corals of the genus Acropora). They suffer high mortality outside of their corals, and as such rarely move between corals once they have established themselves. I have observed up to 16 species of coral goby at Lizard Island which range in social organisation from strictly pair-forming species (which I will refer to as ‘Asocial’ species) to highly social species which can be found in groups of 12 or more (the largest group I’ve found was over 20 individuals).

slide4During my studies, two cyclones have impacted my sites at Lizard Island which has been quite disruptive to my research, but has also presented a rare opportunity to gain an insight into the rarely studied effects of cyclones on social organisation. There is no doubt (unless you’re a cyclone skeptic) that cyclones cause severe damage to the physical structure of the reef. This destruction obviously has impacts on the abundance, diversity and distribution of reef species following the event. For example, obligate reef-dwelling species (species which depend on the structure of coral reefs for protection and food) tend to decrease in abundance while algal grazers tend to increase in abundance. However we know relatively little about how these events affect social structures of reef inhabitants which is a potential driver of the diversity and abundance patterns we observe. As I previously mentioned, social organisation is important in determining factors such as reproduction, foraging success and survival, all of which are critical for a species’ recovery from a major disturbance.

Methods and Results

slide5

We have been surveying sites around Lizard Island since 2014. During these surveys we search each Acroporid coral on our transects for coral gobies. We identify the gobies to species and count the number of individuals living within each coral head (which constitutes a group). We also identify the coral to species and measure it along three axes to estimate an average diameter. I’ve used average diameter in my research so that my findings are directly comparable to previous work which has used this measurement.

The next few slides show some graphs and conceptual diagrams in which I’ve tried to use consistent symbols which I’ll briefly explain. The yellow fish represent ‘asocial’ species (they’re actually pictures of Gobiodon axillaris, a strictly pair-forming species). The green fish represent the social species (these are pictures of G. erythrospilus which is often founds in groups of 3 or 4). I’ve used a little cyclone symbol with an arrow on the graphs to indicate when a cyclone affected the field sites.

slide6We found that social species decreased in group size following each cyclone while asocial species group size remained the same. This indicates that group size decreases observed in social species were unlikely due to direct mortality from the cyclones (otherwise we would have seen a corresponding drop in average group size in the asocial species as well). A year after the first cyclone, the social species had returned to their pre-cyclone group sizes (keep this point in mind as I’ll return to this in a minute). However, a year after the second cyclone the social species had not returned to pre-cyclone group sizes. This may indicate that multiple impacts have longer lasting effects on social organisation.

slide7

Unsurprisingly, we found that coral size had decreased significantly throughout the study. This was the case for for both social and asocial species. The last set of bars on this graph shows the corals that were uninhabited. I’ve included this to illustrate that corals that were uninhabited at the beginning of the study (darkest bar) were of a similar size to the corals that the gobies were inhabiting at the end of the study. This means that at the end of the study, gobies were cramming into small corals that they previously wouldn’t have inhabited.

Let’s return now to that point I made about the social species returning to pre-cyclone group sizes a year after the first cyclone. From the coral size graphs we can see that these larger groups were cramming into smaller corals than before the cyclone.

Why?

I might pause here for a second to explain the underlying mechanism of the hypotheses of social evolution which I have looked at in this study, the ‘ecological constraints’ and ‘benefits of philopatry’ hypotheses. For both of these hypotheses we need to consider the proposition that social groups arise because subordinate individuals make the decision to delay their dispersal (often at a considerable cost to their own reproductive opportunities). The question of why some individuals will delay or forgo their own reproductive opportunities in order to remain within a group is one of the fundamental questions of evolutionary ecology. There are of course other ideas about why social groups arise, but this idea of delayed dispersal is what I will focus on for this study. It is also important to note that these hypotheses are not mutually exclusive and often act together.  So why separate them out? Well, because each hypothesis contains its own set of testable parameters. These parameters can be used to create a statistical model which we test against the real data and we can determine which hypotheses best describe the observed social structure.

Ecological Constraints

slide8This hypothesis looks at ecological factors which might constrain dispersal from a territory such as a lack of available habitat or high predation pressure. In relation to my work, one of the reasons that the social gobies might have re-formed their large social groups in smaller corals could be that they were constrained by a lack of available habitat. i.e. Gobies displaced by the cyclone might have had no choice, but to move into a coral which already had a small group of fish living in it. In this case, we would expect to see that most of the corals would be inhabited because vacant corals would be quickly taken up by gobies dispersing from crowded corals.

Benefits of Philopatry

slide9This hypothesis looks at the idea that animals gain some benefit of remaining on a site that outweighs the benefits of dispersing. For example, the site might be of a high quality which improves the animal’s fitness to survive and reproduce. Dispersing from this site risks, losing this benefit, unless it can find a site which confers the same or better benefits. In my project, it is likely that there was a lot of variation in coral quality following the cyclone. While fish might have quickly moved into whatever shelter they could find, they might have realised later on that their coral was not very good (indicated by the green, algae covered coral in the diagram), and decided that it was more beneficial to vacate their low quality coral and move into a high quality coral (white coral in the diagram) with an existing group of fish. In this scenario, we would expect to find a lower proportion of inhabited corals than we would under the ecological constraints scenario as fish would have vacated low quality corals in favour of high quality corals.

slide10What we found was that after the cyclone, there was indeed a substantial drop in the proportion of inhabited corals. While this doesn’t definitively prove that benefits of philopatry are causing the observed social patterns, it does lend some support to the idea. There was also a drop in the proportion of inhabited corals for the asocial species, but it was not as substantial as that observed for social species. This likely due to a methodological ‘artefact’ which I won’t get into, but suffice to say, for social species, there is some support for benefits of philopatry playing a role in the observed social pattern following the first cyclone. Stay tuned for a more in-depth analysis of this data.

slide11So, in summary, the major findings of this study were that after a cyclone, social species reduced in group size but asocial species did not. A year later social species had returned to their pre-cyclone group sizes, but in smaller corals. There is some evidence that benefits of philopatry are contributing to this pattern. The fact that asocial species did not alter their social organisation could indicate that the asocial strategy is either more robust to such an impact or that it is less flexible. Unfortunately, my surveys were not designed to examine patterns in abundance and I can’t really say whether either strategy is better or worse for recovery following a cyclone. This would be an interesting avenue for further research. Following a second cyclone, social species again decreased in group size, but did not return to pre-cyclone levels another year down the track. This might be because multiple impacts have longer lasting effects on social structure or because corals had reduced to such a small size that they were not capable of supporting larger groups.

Social organisation in social species is influential  in determining survival. The effects of cyclones on social structures has received little attention thus far in the scientific literature. While my research raises many questions, I hope that it can provide a foundation to build upon and move toward  a better understanding of how severe weather events might impact upon social organisation.

I would like to thank my supervisors and field assistants who have contributed to this work. Also a shout out to the Hermon Slade Foundation for funding this research and  the Lizard Island Research Station for accommodating us.

A plea to new spearo’s

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A great weekend diving with friends was somewhat tarnished by the actions of a naive spearfisher. We were unfortunate to witness a spearo enter the water in a sanctuary zone (no-take zone) and spear a blue wrasse, a protected species in NSW.

Spearfishing is a great way to get some fish into your diet. It can be a great challenge learning to freedive and learning to observe fish behaviour. That being said, there are no throw backs with spearfishing. Which is why I implore people new to the sport to know where you can fish and what species are ok to target. Do not pull that trigger unless you are 100% certain that the fish is of legal size and not protected. The fisheries rules are in place to help sustain our fish populations so that everyone can continue to enjoy our oceans.

Getting started can be daunting. It might seem like there are a lot of species to learn and there are. I would recommend tagging along with someone more experienced until you get to know your local fish. Join a spearfishing forum – there are often people looking for buddies. Failing that, get out and go freediving without the spear and look up the fish you see. In only a few dives you will quickly learn the common fish at your local sites. If you really want to get straight into it, consider deciding on a specific species to target before you even get in the water. Failing all of this, you can follow 1 simple rule: If you don’t know what it is, don’t shoot it. 

Some useful websites:

DPI Fishing rules – http://www.dpi.nsw.gov.au/fishing/recreational/fishing-rules-and-regs/saltwater-bag-and-size-limits

Marine protected areas – http://www.dpi.nsw.gov.au/fishing/marine-protected-areas

Spearfishing forum – http://www.spearfishing.com.au/sf-forum/

Shark!

Did that get your attention?

There has been a lot of media attention surrounding sharks recently, starting with that terrifying footage of Mick Fanning and a number of incidents on the NSW north coast. Following on from these incidents there have been calls from a very vocal minority of ocean users to ramp up efforts in shark control measures. It should come as no surprise that I don’t support lethal methods of shark control. As far as I’m concerned there are much bigger risks in life than the threat of being bitten by a shark. If we wish to enjoy the ocean we should know the risks and accept that we share this wonderful environment with these apex predators. However, with all of the media hype, it’s easy to forget that we also share the ocean with some other amazing animals, which is what I though I’d share today.

The beauty of the ocean never ceases to amaze me.

A picture tells a thousand words Jan – Feb Lizard Island trip

I was joined by my sister, Kaz (author of the Madagascan Adventure series) on my latest field trip to Lizard Island. We repeated the surveys that Kylie, Grant and I had conducted last time and ran an experiment to investigate whether a subordinate fish would decide to move out when exposed to an adjacent coral of varying size and with different numbers of fish already residing in it.  I hope you enjoy this visual expose of our time there.

Life at Lizard

The Experiment

For a brief description of the experiment we ran see here.

Day Reef trip

We were honoured to be invited by Anne, Lyle and Alex for a trip out to Day Reef on our day off. It was meant to be a dry day for us, but we were willing to make the sacrifice!

A small win for the PhD!

I had a small win this afternoon!

I’m back on Lizard Island at the moment and over the last few days I’ve been setting up an experiment.

??????????????????????????

This experiment is to try to determine what factors might influence a subordinate individual’s decision to either stay within a group or to move out. I am testing habitat size and habitat saturation. To test these factors I have created groups of three fish (two adults and a subordinate) in medium sized corals. These groups of three are then presented with either a small, medium or large coral containing either 0, 1, 2 or 3 other fish.

Wow! that’s confusing when I write it all out. Here’s a diagram of my experimental design.

Experimental design

Over the last 48 hours Kaz and I have had the first trial running. In trial 1 the group of three fish were presented with an empty coral which was smaller in size. Last night the subordinate actually moved into this smaller coral. I can’t really draw any conclusions from this one trial, but if we keep seeing this happen, it could indicate that the degree of habitat saturation is more critical than the size of the habitat in determining whether a subordinate will stay or leave a group. In terms of group formation, it could indicate that groups are more likely to form when the habitat is highly saturated (i.e. when there are not many vacant corals). That’s exciting for me and my thesis 🙂

More info on my research

My research

Initial project report

Lizard Log series starting here

Lizard pics

Fish tattooing

Fish tattooing

Capturing the fishies

Capturing the fishies

Goby hunting.

Goby hunting.

Kaz shopping for corals

Kaz shopping for corals

Kaz measuring

Kaz measuring

It's not paradise every day...

It’s not paradise every day…

A Madagascan Adventure: Part 2

Part 2: Life as a volunteer

Picking up from where I left off in the last post, after our sojourn through the Madagascan countryside, our initial culture shock somewhat subsided; my fellow volunteers and I were finally in Andavadoake – our home for the next 6 weeks (for some of us, the next 12 weeks). Following that first hypnotic sunset, it was time to get stuck into life on site. Our living conditions were basic but comfortable, with huts situated right above a small cove called half moon beach. We’d wake to the sound of the waves and passing pirogues (wooden sail boats) heading out for the day’s fishing.

Beach Huts

Home in Andava

Our diet consisted of mainly fish, beans and rice, with a few variations on the theme from time to time, including the delicious Malagasy beef equivalent – zebu; The mighty zebu is also used to draw carts, plough fields and buy wives and is a precious commodity for many tribes in Madagascar. I couldn’t get enough of the fresh seafood, though we did miss the abundance of fresh fruit and veg we’re used to back home.

But basically, we were living in paradise!

Zebu

The mighty zebu

mackerel

Freshly caught lunch

A typical day consisted of 2 dives in the morning, many with whale sightings on our ride out to site, a stroll to the village for a cup (or five!) of peanuts, study/hammock time followed by duties, lectures, presentations or language lessons then dinner and ‘tantara’. Tantara roughly translates to ‘story’ in English, and we all took turns to tell a story, run an activity or game, show some pictures etc. for our evening entertainments

A typical week was diving Monday-Friday, Saturday land based activities like visiting mangroves or learning to cook samosas and boko boko (deepfried dough filled with chocolate – yum!), followed by a night of shaking our butts Vezo style in the local bar, Dada’s… the Malagasy’s put us Westerners to shame! Those guys can seriously move. Sunday was our day off where we got to go exploring! We embarked on baobab walks, whale watching, spear and lobster fishing, island picnics, snorkeling trips and even an overnight camping trip on a nearby island. One of the highlights of the trip!

making samosas

Making Samosas. Photo by JD Toppin

(for more adventures, check out JD’s travel blog here)

camping

Camping at Nosy Ve

We were assigned English partners and spent three sessions a week imparting our knowledge of the English language onto them with varying degrees of success. During the expedition my English lessons consisted of the pleasure and delight of trying to decipher then reinterpret the PADI divemaster manual for one of our boat drivers and dive master in training, Patty. Challenging? Yes. Poor Patty. I think I successfully confused him rather than enlightening him! If you’ve ever read a PADI manual, you may understand my struggle.

But back to my reason for travelling to Madagascar – the marine environment. I was here to count fish! As a volunteer, I had to learn 150 fish species along with 36 benthic and invertebrate species. Thank goodness our coral ID was limited to 11 hard coral formations and simply, soft coral. We didn’t have to be species specific. Those scientific names may have killed me! As it was, when I closed my eyes at night, I would see fish and corals flying at me and I’d be chanting names over and over in my head!

Luckily for me, I’ve been plaguing my brother with fish questions over the years of diving together, so I had a basic knowledge of some fish families before we even started, which was an advantage. But when it came down to species level, I still needed work, especially as not all the names were the same – moon wrasse became crescent wrasse, leather jackets became filefish, bullseyes – sweepers, flutemouth – trumpetfish…

Benthic on the other hand, was a bit of a struggle. I’ve never been overly enamored with benthic life, accepting kelp and sea grass, sponges, and corals as an important part of the ecosystem, but indifferent to their actual role and avoiding invertebrates such as sea cucumbers like the plague (ick!). However, our passionate field scientists were somehow able to convince me that benthic was cool and I subsequently looked forward to a bit of benthic surveying.

Goniopora

My fav coral species, Goniopora; despite it’s appearance, this is a hard coral! Image from Wikimedia Commons

I even overcame my fear of sea cucumbers one spring tide, when we helped the aquaculture farmers with their data collection. I opted to be the weigh-er, thinking it would be the best job to avoid handling any squishy, slimy, boneless creatures. Turned out, I had to pick up every. Single. One. Not once, but twice! After a few girly squeals, I managed to get into the swing of things. I can’t say I love them as a result, but I don’t have that fleeting moment of panic when I see them now.

seacucumbers

Zanga! (Seacucumbers)

The sites we dived ranged from healthy to pretty destroyed. The ones that didn’t look so great were affected by a combination of cyclone and storm damage plus destructive fishing practices and overfishing. Education and subsequent dinas (local laws) are in place, to outlaw destructive fishing methods such as poison fishing and beach seining. This has improved the health of the reefs in many areas, which is encouraging to see. Most sites were populated with small to medium reef fishes such as schools of snapper, fusilier, parrotfish and many species of wrasse. But the best part was diving in the protected areas and seeing HUGE fish, such as blue spined unicorns, often in schools, which seemed to be a sign that the protection zones were working! Win!

snapper

School of snapper. Photo by Niki Boyer

Diving with species knowledge really made it such a rewarding experience. It was always exciting identifying something you hadn’t seen in the water before, or something you struggled with! And I had some really special encounters including seeing a turtle – turtles are rare as they’re hunted as a coming of age ritual – hearing humpback whales sing quite regularly, a myriad of new nudis (colourful seaslugs), schooling, yes schooling Moorish idols, and even a sailfish!!

nudibranch

Some kind of Halgerda Nudibranch. Photo by Niki Boyer

Expedition life was an incredible existence for me. So far removed from my everyday reality in Australia. It was refreshing to be learning again and to be immersed in a culture and way of life I never knew existed. I will talk more about the people of Andava in my next post…

THINGS I MISS…

Being in or on the water every single day!

The infinite stars at night

Watching pirogues sail by

Constant sound of the ocean

The pace of life

The vazah and vezo friends I made

My hammock

Kids yelling ‘Salama’ everywhere you go

The dancing!

 

THINGS I DON’T MISS…

Sand in my bed

 

hammock day

View from my hammock

hammock sunset

Sunset from my hammock

stars

Stars! Photo by Ben Large

Initial Project Report

Slide1

Last week I presented at the University of Wollongong Post-Graduate Conference. I have adapted my presentation below as it was a good overview of my project to date. By way of some background, each year the biology post-graduate students are set a challenge to incorporate an object or personality into their presentations. This year it was Leonardo Dicaprio, so keep an eye out for some celebrity cameos.

So without further ado, let’s start this talk by having a quick think about why animals form groups. We might imagine that in a perfect world, the ideal way to ensure that you maximise your genetic contribution would be to breed as soon as possible and as many times as possible. This would involve leaving the natal territory as soon as possible to pursue individual breeding opportunities.

Slide2

So why then do we see so many examples in nature of reproductively mature animals which routinely delay or (in extreme cases) completely forgo their own reproductive opportunities in order to join and remain within a group as a subordinate non-breeding member?

The answer is that we don’t really know. We have a few ideas and theories about the costs and benefits of group living, but a general explanation has remained elusive. A major obstacle standing in the way of achieving a general explanation is that there are a lack of studies on marine organisms, which is what my study will focus on.

One of the most promising frameworks with which to study this behaviour is the cooperative breeding framework. This framework contains several hypotheses. I’ll go through just a few which I would like to test and which I will refer to throughout the presentation.

1) Ecological constraints – EC looks at a situation where ecological factors force animals into groups. eg. high predator abundance might cause animals to group in order to obtain a protective benefit through the dilution effect or by making use of discrete habitat patches which provide defence.

2) Life-history – LH hypothesis and EC are closely linked. LH hypothesis looks at inherent life-history traits of animals which might lead to a situation where group formation if more beneficial. For example, animals with long life-spans might cause a breeding habitat to become ‘saturated’. i.e. no vacant breeding ground for new recruits to make use of. In this case it might be more beneficial for the next generation of reproductively mature individuals to join a group and wait for the breeding habitat to become available (avoids conflict).

Most of these studies on birds, insects and mammals to date have either been broad phylogenetic comparisons or fine scale experimental manipulations. Both methods have merit and have in fact been responsible for the huge advances in this field, but there are few studies combining the two approaches. It is important to combine these methods as the broad scale studies can draw correlative conclusions across multiple taxa, but they don’t offer causative explanations. Which is where the experimentation becomes important. However, fine scale experimentation can only focus on a few taxa so the results are often difficult to apply generally across multiple taxa.

So how am I going to approach this question?

I will use a genus of coral reef fishes which show considerable variation in social organisation as a model. Gobiodon species are found in high abundance on tropical reefs. There are over 20 known species.

Slide3

I will start by conducting a broad phylogenetic comparison of the Lizard island population of Gobiodon. This will involve making a genetic phylogeny of the species at Lizard Island (the above picture shows the phylogeny of the Red Sea population). Phylogenies show how closely related species are to each other. Species radiating from a common node are more closely related to each other, than to species originating from other nodes. The nodes represent some common ancestor. Looking at where sociality occurs on this phylogeny is important as we can see whether the behaviour arose at a single evolutionary point or whether it has evolved multiple times. Looking at the tree above, social behaviour does appear to have evolved multiple times.

Using this phylogeny as a base, I can map ecological and life history traits of each species. This will show which traits the social species share and which the asocial species have in common with each other. I will use this information to identify traits to manipulate experimentally to try to induce social behaviour in an asocial species or vice-versa.

I have chosen these fishes because they show great variation in social structure. for example G. histrio is stubbornly pair forming like Romeo and Juliet. While G. rivulatus forms large social groups more akin to the Great Gatsby, although I suspect that there might be some reproductive shares going to subordinate individuals in the Great Gatsby…

Slide4

But back to Gobiodon; they are also highly site attached, which makes observing and cataloguing their social systems, ecological traits and life history traits far simpler and experimenting logistically easier with them. Once they have chosen a coral to settle in, that is where they stay. Even when the water level drops below their corals during extreme low tides, they will hunker down and remain within the coral, exposed to air for a couple of hours. They have a high hypoxia tolerance and air breathing ability which enables them to do this.

Slide5.1

I have chosen Lizard Island in far north queensland as my study site because:

Slide5.2

Click to enlarge

a) it has an exclusive resort where celebs like leo can be found. Unfortunately, they don’t let the researchers stay here. They tuck us around the corner in this photo.

 

 

 

Slide5.3

Click to enlarge

b) most of the species of gobiodon are known to occur here (and possibly a new species). It’s also worth noting the size of these fishes in the picture below. The fish in the second and fourth pictures on the top row are actually sitting on my gloved hand.

 

 

Slide5.4

Click to enlarge

c) There is a well established research station here run by the Australian Museum which makes field work and experiments much easier.

 

 

We started this work by finding Gobiodon colonies around lizard island and capturing, counting and identifying the species. To capture the fish we use a mixture of clove oil and ethanol which anesthetises the fish and then we ‘waft’ them out of the coral. Once we capture the fish we hold them in plastic bags until the end of the dive and then take them to a boat to be processed.

Slide7

To build the genetic phylogeny we need to obtain genetic material. I’ve been taking fin clips from the fish for this. We just snip off about 1/8th of the caudal (tail) fin area while the fish are anesthetised. It’s not uncommon to see these fish with much larger chunks taken out of their fins, usually from conspecific disputes. The fins do grow back quickly so we’re not doing any permanent damage to the fish.

While we have the fish on board and anesthetised, we measure their SL and TL and we give them little tattoos. These are a flourescent elastomer tag inserted under the skin so that we can identify the fish again when we come back in order to determine some life-history traits like dominant turn over rates or growth rates or mortality.

To collect the information about the ecological traits to map onto my phylogeny, I have been seeking out Gobiodon colonies and taking Coral measurements.

Slide8

To measure habitat saturation we have been using x-transects centred on a colony of Gobiodon. We move along each axis of the transect and catalogue all of the corals known to be inhabited by Gobiodon species. We record whether they were inhabited or not, what they were inhabited by, how many individuals are in each coral, the size and species of each coral.

This gives us an indication of how many and what types of colonies are surrounding the focal colony and how much available habitat there is in the immediate area.

I need to complete the phylogeny now to map these LH and ecological traits and see if there is any correlation between sociality and these traits.

Slide9.1

The downside to working in beautiful tropical locations is that they are prone to cyclone activity.

Cyclone Ita came right over Lizard Island in April this year. The photos below are taken from the same sites (left to right) before and after the cyclone. In February, my assistants, and I had tagged about 600 individual fish with a plan to come back in 6 months to re-capture and re-measure these individuals and determine growth rates and dominant turn over rates. I returned in August and found 8 of the original 600 tagged fish.

Slide9.2

But moving on, I am still interested in the evolution of social behaviour in these fish, but I will focus more on the evolutionary advantages of sociality or asociality in re-colonising a reef after a disturbance. And I’m hoping that I’ll be able to see that recovery in the data coming out of the x-transects that we’re using to measure habitat saturation.

Anecdotally, there appeared to be more uninhabited corals than there were in February, though I can’t verify this statistically because I used different methods (we were looking at a different question in February). There also appeared to be more juveniles present in August than in February.

Slide10

Moving on to some preliminary results, these tables show the results from a statistical method called a Generalized Linear Model or GLM for short. Don’t worry about that or all of the technical looking numbers, all you need to know is that a significant result is indicated in red or a highly significant result in yellow. For most of the species above, there is a significant result for average diameter of the coral. That just means that there was a strong relationship between the size of the coral (the predictor) and the number of individuals living within the coral (the response). i.e. the size of the coral could be used to predict the number of fish living within it for those species with a significant result.

I’ve found that the group size of some of the social Gobiodon species is related to the coral size, but not to the size of the largest individual (alpha), which is interesting as Marian Wong and Pete Buston (who presented at UoW a couple of weeks ago) had found that there was a relationship between both coral size and the size of the alpha with the group size in the anemone fish Amphiprion percula. G. oculolineatus does appear to follow this pattern. What I can take away from this is that the determinant of group size is probably species specific and will therefore be more difficult for me to make general conclusions about.

Looking at some of the before-after cyclone data that was comparable, the corals that did survive the cyclone showed positive growth. However when we looked at the site as a whole, the average size of the corals had decreased. This was to be expected since, as you can imagine, a major disturbance like a cyclone would smash up the larger corals into smaller corals. The smaller corals also have less surface area so are more likely to survive a cyclone.

Slide11

I’ve also found that, as you would expect there was a decline in the coral goby abundance. However, the second graph is more interesting. Some species, like G. erythrospilus, G. rivulatus and G. unicolor appear to be occurring in larger groups post-cyclone. This is possibly an indication that they are in a phase of recruitment.

Slide12

This will require further exploration so I have another trip planned for January. During this trip I will be re-conducting the x-transects in order to examine this trend across multiple sites. What I will be looking for is whether there is a detectable shift in the goby community. There might be a higher proportion of social species present which could indicate that social species have some kind of advantage in recolonising a reef after a disturbance (or vice-versa).

Slide13

I will now need to finish the genetic phylogeny and map on the ecological traits that I have collected so far. I have another round of field work booked in for January. I will be conducting more of the cross transects to see if there has been a detectable community shift since my last visit. I also want to set up a pilot experiment looking at the effects of habitat quality and habitat saturation on a subordinate individual’s decision to move or not.

I would also like to set up and run the life history traits work again. i.e. the capturing and tagging component, as this is a really important part of the cooperative breeding framework which I’d like to explore.

To finish up I’d like to say a final thank you to my assistants for their help in the field. It really is a big commitment for them to come and help me out for weeks at a time. Thank you very much! My work could not happen without your help.

Slide14

If anyone has any questions about my project, please leave a comment below. Thank you!