Snapper are serial spawners and their reproductive strategy is to mass-produce their eggs and broadcast them over a wide area in the hope that a few of their offspring will survive. This is one of nature’s clever approaches to survival of a species. In the case of snapper, it works, because there is a high rate of mortality for the baby ones (like in the larvae stage) that don’t make it.

What are the odds of surviving? Well not too different to winning the lotto. That kind of puts things in perspective when it comes to looking after the undersized fish that we release. We need to first respect that those little goldfish were pretty lucky, until they ended up on our hook.

If the chances of dying are so high, how do we increase their chances of survival?

Using lures when fishing will catch fewer small snapper and lip hook them more often which gives them a better chance of living when released. Filing or crushing down the barb will make it easy to remove the fish from the hook. It can be quite harmful for the fish to be firmly squeezed as a large-handed fisher tries to rip a hook out of its jaw because the barb keeps catching on its skin.

Steady pressure on the fish when pulling it to the boat (or shore) will mean barbless hooks will still catch as many as those with a barb. In fact, there may be an argument that barbless hooks have more success because it is easier to penetrate the fish’s mouth because the barb is absent.

If you can release a fish whilst it is still in the water, even better. If it is a stroppy little fighter and you foresee a few spines in the finger as it struggles for freedom, holding it in a rubber mesh net and using a pair of pliers is the safest approach for both fish and fisher.

A word of warning – please don’t use a dry or wet cloth when holding fish prior to release. The fabric can remove the precious mucus from the fish and make it susceptible to infection on release. The mucus helps provide a barrier for disease and if this is removed by rubbing or if scales are lost because of flapping around and banging against the boat, it can be the end of the fish.

It has been popular practice to use a cloth, but it isn’t best practice so please instead try the above first – remove your barbs so releasing the fish in the water is easy, use a rubber net to contain stroppy fish and as a last resort use wet hands to handle fish. You can use the cloth on your hands afterwards, but please don’t use it on the fish. Summertime can be the time of lots of baby snapper make a nuisance of themselves but remember those were the very lucky ones, ensuring their survival can only do good for our fishery.

Selective breeding in fish – written by Anna Blair

According to Darwin’s theory of evolution, the most successful organisms will survive to thrive and pass their genes on to the next generation. While environmental factors are normally the major determinant of reproductive success, when we interfere with natural selection, the gene pool is altered, a process termed Human Induced Evolution.

Selective agents

We tend to act as selective agents when fishing because there is a natural tendency to think that ‘bigger is better’ and to place a high value on ‘PB’s’ for different species. Large trophy fish often end up on the scales – most fishing contests bear witness to that observation.

Removing a disproportionate number of fish with certain genes from a population means those genes are not passed on in the same proportion to future generations and the percentage of those fish in the total population will decline.

Size-selective harvesting or killing of larger fish means a shift to greater proportions of smaller fish in the population. These smaller sized fish pass on their genes, so the average size in the population is shifted towards the smaller end of the scale.

Fisheries-induced evolution has been happening for decades and it happens much faster than natural evolution. Archaeological evidence confirms that the average size of snapper was once much larger than it is today. The age, size and weight of snapper at maturity has declined over time with the most likely causes an increase in fishing pressure and advances in technology.

Shrinking populations

Fisheries-induced evolution poses a threat to the future state of fisheries, affecting yields, stock stability and recovery potential of populations. Size-selective harvesting may cause fish populations to reach maturity at a younger age and smaller size, at which the individuals have lower productivity.

Large female fish produce more eggs and larger males produce more sperm, so the number of offspring per head of population tends to be larger than with populations containing smaller sized fish. Larger males also tend to be preferred by females and have more reproductive success than smaller male fish.

Genetic diversity is critical for the health and success of a population because it is the raw material for evolution. Genetic traits are naturally selected for or against, based on fluctuations in environmental conditions. A reduction in genetic diversity results in decreased ability of individuals to adapt to changing conditions: fewer individuals will survive in the event of environmental change and population size decreases. The fish that do survive to produce offspring pass on similar genes, contributing to greater genetic uniformity.

The cycle repeats, making it more difficult for a species to return to the productivity and diversity it once enjoyed.

Not only does fisheries-induced evolution have a negative effect on the fish populations themselves, but it also has social and economic implications, such as decreased commercial fishing potential and a reduction in the contribution of recreational fishing to New Zealand’s economy.

Norway’s cod

An example of fisheries-induced evolution has been exhibited in the case of the Norwegian cod stock. Large fish are prized in Norway and fetch higher prices at fish markets. The cod stock has undergone multiple declines since the first quota was introduced in 1978, and since 1930 the average size and age of sexual maturity in cod has decreased significantly.

Doctoral research fellow Anne Maria Eikeset of the Centre for Ecological and Evolutionary Synthesis published findings that suggested evolutionary change, as a result of the boom in the commercial fishing industry, is the culprit. As large fish go for the highest price, their genes for large size, increased reproductive success and later sexual maturity have continuously been removed from the population.

The fact that changes are being made at the genetic level means fishing, both recreationally and commercially, is affecting species more than we have been aware of. While some populations may be able to recover in terms of biomass, it is unclear whether reversals in terms of genetic diversity are possible.

Research models produced by various groups indicate that several years of evolutionary recovery will be required to restore populations to their highly productive and diverse states for each subsequent year of exploitation at its current rate. This ‘Darwinian debt’ will need to be repaid by future generations that are already suffering from other effects of environmental neglect.

Fish for the future

So, what can we do about it? Fortunately, there are a few ways we can aid the recovery of our great New Zealand fish populations and reduce the amount of genetic diversity lost through fishing. We already have a size limit on the lower end of the scale, so maybe an upper size limit could be introduced during breeding seasons to allow big fish to reproduce and pass on their genes.

Releasing large fish will also be important and fortunately a change of attitude around killing the big ones is starting to filter through to most anglers.

Competitions should focus on sustainability rather than kill and weigh. Again, there’s a real shift to using measurement as the criteria for angling achievement. Today’s technology makes it easy to photograph a fish on a measure and have that recognised, but also allows big fish to be released to breed.

The DB Export NZ Fishing Competition is a good example of the use of technology to empower anglers to make their own decisions on what’s best for the fishery and sustainability.

We have an opportunity to make a positive change for future generations – letting some of those big catches go is worthwhile for the benefit of the future keen anglers of New Zealand.

So, when you tick off that bucket-list goal of a 20lb snapper or a 30kg kingfish, if it’s in good condition, maybe it can go back to keep those large-growth genes in the pool!

Anna Blair is studying genetics at Otago University.

This article is the property of NZ Fishing News and has been reproduced with their kind permission.

For more fishing related information, check out the NZ Fishing News website to subscribe for thier print or digital publications: NZ Fishing News

This article is the property of NZ Fishing News and has been reproduced with their kind permission. Written by Bruce Hartill from NIWA, this article gives excellent information on the effects of barotrauma and how fishers can minimise harm to any fish suffering from the change in pressure when retreived from depths greater than 20 meters.

For more fishing related information, check out the NZ Fishing News website to subscribe for thier print or digital publications: NZ Fishing News

This article is the property of NZ Fishing News and has been reproduced with their kind permission. Written by Tom Lusk, this article gives excellent information on how to extract the most food from your catch so nothing is wasted. Making the most of each fish shows maximum respect for our valuable fishery.

For more fishing related information, check out the NZ Fishing News website to subscribe for thier print or digital publications: NZ Fishing News

FishCare was part of the LegaSea stand at the Hutchwilco New Zealand Boatshow. With numerous attractions at the stand, FishCare engaged the public to better understand their fishing habits with a quick survey. Approximately 6000 stopped and talked or spent time with us, learning about measures and ways to help our fishery.

The alluring smell of smoked fish wafted around the FishCare tent and across the boulevard drawing in curious crowds at the Westhaven Marina Open day Sun 10^th March.

The kai cooker heated up smoked fish heads which were then broken down and handed out to passersby. Smoking a fish is a great way to utilise every part of it, including the head and the frame. It isn’t uncommon for fishers to fillet fish and discard the rest.

The FishCare team engaged the public on the importance of showing respect for the fish, our community and ourselves by utilising everything (smoking being one easy way to do this). Another way to ensure full utilisation is using the Freefishhead.co.nz website to find people in the community who would gladly use the heads and frames. The public were highly receptive to nibbling smoked fish and discussing the principles of utilisation.

FishCare attended the Outboard Boating Club’s Family Fishing Competition, Mar 9^th . This was the first time this annual event had been run as a measure and release format. Measure and release competitions have a lot of benefits for our fishery, particularly as it means fewer fish are killed and potentially none are wasted. Fishers can catch fish and be eligible for a prize but they can also choose which ones they want to keep to take home to eat. The rest can be returned to the fishery.

FishCare sponsored a section in the competition, where entrants could submit a photo of their catch being released, displaying best practice handling and release techniques. Despite the weather being uncooperative, there was a solid number of entrants and the late afternoon festivities finished off the event in good cheer.

Sometimes we leave behind traces of our fishing trips in the marine environment. Plastic bags can blow into the water without our noticing them, or we cut a tangle out of our line and throw the offending mess into the sea. We may get snagged on the bottom and leave behind a lure and section of line that could end up wrapped around some sea creature’s head.

Accidents do happen, but we can certainly minimise the impact we have in the marine space. Making sure that plastic is not left lying around on the rocks or our boat is an easy one, simply because as we fly home with our eyes glued ahead, the wind may catch a bag sitting on the floor behind us and whip out onto the ocean without being noticed. Minimising plastic on board in the first place is a good idea too.

Recently, a fisher was doing a beach clean-up along the Thames coastline and couldn’t get over the number of red onion sacks washed up on the shore. Fishers use these as berley bags and had simply discarded them after a day’s fishing. It was obvious fishers would rather pollute the environment instead of getting their hands dirty and emptying the berley bag of its contents before stowing the plastic onboard for proper
disposal.

It’s a good idea to have a rubbish container on board that is easily accessible so line,  packaging, and items such as used softbait tails, can be safely stowed away. Any measures that prevent rubbish from
entering the sea contributes to reducing our impacts. Softbaits have become very popular over the last few years and this raises the question around pollution. Some brands are biodegradable and will likely say so on the packaging. While not as bad for the environment, it is still best to not throw them overboard once they have served their purpose because the time it takes to biodegrade can still be a while.

The Papatuanuku Marae have once again attracted praise and support for their initiatives to help their community reconnect to healthy food. By collecting and distributing fresh fish heads and frames shared by the OBC (Outboard Boating Club), the Marae have been helping more than 60 families get nutritious food into their diet. Check out the stuff article here.