The state of fish populations in the Mediterranean (and the Black Sea) is the worst in the world, with 62.5 percent of them being overfished, according to a new report published by the Food and Agriculture Organization of the United Nations (FAO).
This publication joins a long line of articles and reports pointing out that uncontrolled fishing leads to a decline and even collapse of many marine animal populations, first and foremost fish.
Until the late 1990s, the commercial fishing industry was considered to be primarily responsible for the ongoing damage to fisheries, but since the beginning of the 2000s, according to numerous studies on the subject, the sport fishing industry has also been added to the list of those responsible.
Sport fishing accounts for 15 to 36 percent of the total annual fishing catch (including commercial fishing) off the coast of Israel's Mediterranean coast. In Israel, about 70,000 fishermen are active in sport fishing, according to estimates recently published in a sport fishing survey.
The catch is divided as followed: shoreline fishing amounts to 147 and 203 tons of fish per year, while offshore fishing, which is more difficult to document and evaluate, between 70 and 588 tons per year.
The main species caught using a fishing rod from the shore are Surf Parrotfish (Siganus rivulatus), White Seabream (Diplodus sargus), Northern Whiting (Sillago sihama - migratory species), Flathead grey mullet (Mugil cephalus) and Sand steenbras (Lithognathus mormyrus).
Catch, release and injure
Sport fishing is carried out in two main methods: fishing with a rod from the shore or a vessel and fishing with a harpoon while free diving.
Most of the catch is taken home by the fishermen for private consumption. However, smaller fish species, below the minimum size allowed to catch, and protected species have to released back into the sea.
This method is called "catch and release" and its purpose is to minimize the damage of fishing, with the common explanation being that most of the time, the fish will return to the area where it was captured and return to its population.
But many studies in different parts of the world show that even during this method, the fish are seriously injured and sometimes even die. The average mortality rate of fish that have been caught and released is 16-18 percent, but for some sensitive species, the mortality rate is even higher than 90 percent.
"In recent years, there has been a very large increase in awareness of the environmental repercussions of fishing in general and sport fishing in particular," says Erez Yeruham, a marine ecologist at the Society for the Protection of Nature in Israel and doctoral student at Israel Oceanographic and Limnological Research Institute.
"But it should be understood that regular catch and release cannot be carried out without consequences," he says.
According to the SPNI, the use of the catch and release method has increased in the field of sport fishing in recent years. Today about 64 percent of the total fish caught with fishing rods in the United States and about half of the fish caught that way in Europe are released back to sea.
In their recently published report "Capture and release of marine animals in the framework of fishing," SPNI says that the extensive practice of catch and release negatively impacts both fish populations and entire ecosystems.
According to the document, catch and release, which is mainly practiced in fishing with a fishing rod, can cause a wide range of injuries of various types to the caught fish: the most obvious damage is bleeding and tissue damage caused by the hook.
Particularly vulnerable are predatory fish that capture their food through an extendable jaw, such as stings rays. Fishhooks might puncture their jaw and cause injuries to the mouth, making it difficult for them to obtain food during the recovery period.
Aside from increased mortality resulting from these injuries, in the long run, the fish that survived the release may suffer, among other things, a decrease in reproductive potential and behavioral changes such as changing migration patterns.
"On a large scale, catch and release can harm entire populations," says Yeruham.
"Studies have shown how in places where catch and release is the only allowed fishing practice, there was still significant damage to populations, which was reflected in a decrease in the number of fish and a change in population distribution - similar to damage due to high fishing pressure," he says.
"It is difficult to determine the exact impact of sport fishing," says Ori Frid, who coordinated and wrote the sport fishing survey conducted at the initiative of the Nature and Parks Authority and the Fisheries Division of the Ministry of Agriculture and in collaboration with Tel Aviv University.
"However, we have seen that in relation to commercial fishing, the average catch of sport fishing is very high. In addition, the released fish does not necessarily survive - they do return to the sea, but most of them experience severe physical injuries."
According to studies and reports from recent years, the catch of fish in the Mediterranean is declining, mainly due to over fishing. In addition to damaging the food supply, the entire marine ecosystem is at risk: Fish are part of the food web, eating smaller organisms like algae, jellyfish, and crabs.
At the same time, fish are food for species above them in the food web like bigger fish, dolphins, sharks, seals, and whales. If the reproductive capacity of fish is reduced, while the species they feed on may reproduce unhindered, the species that feed on the fish experience food shortages.
This structural damage to the marine ecological balance would ultimately also damage humans – that is, industries such as recreation, tourism, and fishing, not to mention the damage to the services that the sea gives us in the form of carbon dioxide adsorption and climate regulation.
Desalination could also be affected if the quality of seawater decreases, for instance, on account of the overproduction of algae.
License or no license
In Israel, there are two types of sport fishing; one that requires a license and one that is exempt. Licensed fishermen are those who fish from a vessel at sea with the help of a harpoon gun or fishing rod and are required to abide by Agriculture Ministry regulations.
The regulations that aim to reduce the impact of fishing on fish populations and preserve marine ecosystems include limiting the daily catch to 5 kilograms (or two large fish). It is also forbidden to fish during the breeding season and to fish in the areas of marine nature reserves.
Fishermen using a fishing rod from the shore are not required to have a license or comply with regulations.
"Over the years, I have seen the methods of coastal fishermen become more sophisticated," says Eyal Miller, manager of the north marine rangers team of the Nature and Parks Authority.
"Some fishermen bring four or six fishing rods, each rod attached to a machine that could carry weights of 100 kilograms. They'd catch very large and high-quality fish,” he says.
“A lot of fishermen start from the premise that catch and release is an action without consequences, although in practice, the damage to the fish can be significant, even compared to professional fishing," says Yeruham.
“Even fishing restrictions that focus on the size of the fish that are allowed to be caught and limit the amount of catch are based on this erroneous assumption, and in fact, creating a situation of more extensive use of the catch and release method,” he says.
"There is a long list of guidelines that dictate how to perform the catch and release method accurately in order to minimize damage," Yeruham adds.
"You need to know where to fish so that it might not even be necessary to release most of the fish you catch, and to make sure to use equipment that reduces damage," he says.
"For example, it is better to use non-serrated fishhooks because removing jagged hooks from the fish causes much more serious damage. In addition, it is important to hold the fish correctly when out of the water to give it support from the bottom and keep it in a wet and humid environment as much as possible to prevent suffocation.
"But the most important message for fishermen is to understand that this method is not without consequences."
Reprinted courtesy of ZAVIT* Environment and Science News Agency