My Collecting Notes

by Vinny Kutty

The first and most important aspect of collecting techniques is personal safety. It is most important that on arrival at the collecting site you check escape routes from the beach, because your life can depend on it. It is all too easy to become so engrossed in collecting that you forget about the tide coming in. It is a mistake that you may have the chance to make only once. I cannot stress enough the importance of knowing exactly how to get off the beach in an emergency, or of keeping an eye on the tide.

An experienced collector soon develops a sort of instinct for tides, as there is a subtle difference in the sounds of receding and advancing waters. There is a distinct change in the tiny currents of the rock pools, and the pools begin to look different as the rocks submerge. Take only what is absolutely necessary for collecting to the pool, and leave everything else above the high tide mark. If you do not take these simple precautions, the least you can expect is wet feet and the loss of gear. Or you might not be so lucky. Having once been almost cut off by the tide myself, I can assure you that it is not by any means an amusing experience. Remember that the tide comes in about ten times as fast as you think it does, and in flat sandy areas matters are worse. As there are fewer reference points, it is much more difficult to detect tidal movements, and once the tide starts coming in, it moves, in most such areas, at the speed the average person can run unladen.

The first and most popular method of capture of fishes is stalking. This involves moving gently through the water and watching carefully. Movements other than those caused by currents are easily recognised, with a little experience. Once a movement is seen one should remain motionless and look carefully until the fish is located. Most fishes are well camouflaged but spotting them also comes easily with experience. Extreme stealth is now called for, as the fish must not be disturbed in any way, and lateral lines are very sensitive. The large net should be placed as near in front of the fish as possible - normally about six inches. The fish should then be chased gently into the net from the rear with a small hand net. This method is usually effective in trapping gobies and blennies.

The second method is really a variation of the first. Many fishes hide under rocks, and can be flushed out by turning the rock gently over. This can be repeated until you are in a position to revert to the first method. Please remember to replace the rocks afterwards, as it is so easy to ruin a good collecting area by carelessness. Some rocks will be too heavy to move and the flushing out of the fishes will have to be done by hand. Some collectors, in fact, use their hands for this, and it is the most reliable way, but as one cannot generally see what is under the rock, I consider the method inadvisable. I prefer to use a small hand net or a stick. This avoids crabs large and small, weavers, and other nasties. This second method usually results in the capture of eels, rockling, gunnels, blennies and Cottus.

Both of these methods require clear water, so care must be taken when moving about. Stalking can also be used to great advantage at night with the aid of a torch. The fish is located with the torch, and trapped in the normal way. This is generally easier than daytime collecting, as most fishes go into a trance-like state at low light intensity, and are also to a certain extent mesmerised by the torch. They do not normally, in this state, respond to external stimuli, unless extreme danger threatens. If they do react, they will dart away, and immediately resume their trance state.

The third method is that of sweeping the large net through the water, and usually follows after the first and second methods have been used to the full. Clear water is not necessary, and the method is simpler, and often more productive than the first two. The net may be swept rapidly through the water, either in mid-water or across the bottom. This may produce anything from mullet to pipefish, and rockling to gobies (some gobies, such as the beautiful crystal goby, Aphia minuta , swim in mid-water). The net may also be swept along under a ledge, in which case the net should be kept tight against the under side of the ledge. An alternative is to place the edge of the net against the bottom of the pool, about a foot out from, and parallel to, the ledge. The net should then be pushed rapidly forward until it hits the ledge, whereupon it should be dragged sharply upwards, keeping it firmly against the rock. This may also be applied to a rock, wall or breakwater where there is no ledge. The best application for this method is where the ledge or wall is covered with algae. It usually results in the capture of Cottus, wrasse, sticklebacks and the interesting juvenile lumpsuckers, Cyclopterus lumpus.

The sweep method may also be applied to flat sandy areas to catch flatfishes. For this purpose it is as well to dig the net into the sand while sweeping, or the net is liable to ride straight over the top of the fish. One must also bear in mind the legal restrictions on the removal of flatfishes under three inches long from the sea.

There are five more methods of collecting, which do not really come within the scope of this article, but I will mention them briefly. They are (i) skin-diving, (ii) trapping and trawling, (iii) drugging, (iv) angling and (v) concussion.

(i) Skin-diving. There are two basic methods of collecting while skin-diving, the first being with two small weighted hand nets. The fish is trapped between them and transferred to a keep net attached to the diver's belt. The second method is to chase a shoal of fish into a wide drift-type net, which has floats at the top and weights at the bottom, bent into a V shape.

(ii) Trapping and trawling . These are really deep water methods, and the majority of any fishes caught will not be suitable for the home aquarium. Trapping in particular is unsuccessful, as there is very little in the way of suitable bait. Even aniseed does not seem to be very attractive to marine life.

( iii) Drugging. Anaesthetics may be poured into rock pools, but the fishes are then difficult to find, as there will be no movements to identify them. My main objection is, however, that this method is likely to destroy the invertebrate and algal life present, and ruin the whole area as far as collecting is concerned. The most common drug to be used is urethane.

( iv) Angling . This usually produces larger fishes than can be accommodated in home aquaria. Furthermore, the fishes are damaged around the mouth, and the risk of infection is greater in aquaria than in the sea. They will also be suffering greater shock than fish do after netting, and this too will have an adverse effect on their chances of survival.

(v) Concussion. This is carried out by detonating explosives under water. On no account should this method be used, even if you think you are an expert with explosives. It will kill or injure all the fishes, and may do the same for you, or bystanders. It will undoubtedly ruin the collecting area for a long time to come, and will achieve nothing else.

After Capture
To return to the more acceptable methods of collecting that were described above, one must realise that once the fish. is in the net, it is only the beginning, not the end. For the first, second and fourth netting methods, specimens may be removed from the net and placed at once into shallow storage trays.

With the third method, however, it will be necessary to tip the entire contents of the net into a tray for sorting. It is very easy to miss such things as young pipefish and wrasse amongst the rest of the debris when it is still in the net. The storage trays should be kept covered, as seagulls are not averse to free meals. The water in the trays should not be too deep - just enough to cover the fishes - or layers of high carbon dioxide concentration may build up rapidly.

It must be remembered that most marines eat other marines, so be careful which species and sizes are put together. Cottus are remarkable for their capacity. If collecting is carried out on a sunny day, the storage trays must be kept in a shady spot, because the temperature of a small volume of water quickly rises to more than the fish will withstand if left in the sun.

When collecting is finished, the fishes must be bagged up. Polythene bags are ideal for this, as there is less likelihood of bruising than with hard-sided containers. Do not use water from the storage trays as this will have become comparatively foul. Collect the coolest, clearest water that can be found in the pools into the bags. Use only sufficient to cover the fishes, as the air in the bag is more important than the water. Place a very small amount of pure borax in the water, as this will help to maintain a high pH. Place the fishes in the bags, bearing in mind the species and size relationship. A good guide to the number of fishes to pack is 1 inch of fish to 1 inch width of polythene bag, but, of course, this is an average figure, which will vary considerably according to species. The bag must be closed, trapping as much air as possible. This must never be less than twice the volume of water. The top of the bag should be twisted together and either knotted or folded and fastened with a rubber band. When packing Cottus it must be remembered that they have vicious opercula spines, capable of inflicting severe wounds on unarmoured fishes. They are also likely to puncture polythene bags, so it is customary to place the first bag inside a second.

Before leaving the collecting area, the specific gravity of the water should be tested, as it is inadvisable to subject any fish to a change of more than O~oO3 either way. Most fishes will stand much more than this, but it does not do their body chemistry a lot of good for them to suffer it.

The quicker that the fishes are transported home after packing, the better the results will be. The fishes should be removed from the bags, and placed in the tank as soon as possible. Heavy aeration is advisable for the first few hours. If the water temperature in the bag is low, and that in the tank is high, it will be necessary to float the bags for about 15 minutes before release. The reverse, however, is not true, and the fishes will accept a sudden cooling without trouble.

The collecting of your own native marine specimens is a very rewarding aspect of the hobby, and the fishes are more interesting than most people think.


First published in the newsletter of The Vancouver Aquatic Hobbyist Club