Fisheries Exploitation

by tsqui2 on February 8, 2015 - 6:15pm

Commercial fisheries exploitation is a common theme among the majority of target marine species. Every day fisheries products are utilized all over the world: direct human/animal consumption, fish meal, fish oil, food additives, medicine etc (Bostock et al. 2010). However, the majority of fisheries consumers don’t have an understanding of commercial fishing’s environmental short-comings.

50-80% of all life on earth is estimated to reside under the surface of Earth’s ocean (MarineBio). Exploiting habitat that is home to the majority of all biota on planet Earth may not be the best method for biodiversity preservation. There are many examples of man overfishing a desirable fish species close to, or to extinction. The orange roughy, Atlantic cod and blue fin tuna are examples of species for which commercial overfishing has dropped populations into an exploited state. Overall, 80% of fish stocks (where information is available) are overexploited or fully exploited (United Nations).

Internationally, fishery regulations are difficult to impose, increasing conservation difficulty. Currently there are some countries that impose marine protection zones where humans are prohibited. Simple efforts like these are a good start for the preservation of marine diversity, as long as everyone participates. As a result, commercial fisheries have become a tragedy of the commons. Finally, where should conservation effort be focused to please as many stakeholders as possible?


Bostock, J., B. McAndrew., R. Richards., K. Jauncey., T. Telfer., K. Lorenzen., D. Little., L. Ross., N. Handisyde., I. Gatward, and R. Corner. 2010. Aquaculture; global status and trends Philosophical Transactions of the Royal Society, 365:2897-2912.

"Little Known Facts About the Ocean." N.p., n.d. Web. 8 Feb. 2015. <>.

"United Nations: Resumed Review Conference on the Agreement Relating to the Conservation and Management of Straddling Fish Stocks and Highly Migratory Fish Stocks." N.p., 24-28 May 2010. Web. 8 Feb. 2015. <


Dear tsqui2,
I thought you article was a very interesting read about the exploitation of fisheries and the destruction of habitat which is home to 50-80% of biota on earth. As well as that I thought asking the reader “where should conservation effort be focused to please as many stakeholders as possible” as the end of the article was clever as its het the reads mind going. In terms of your use of language I think it was great that you managed to simplify everything in to laymen’s terms so that anyone could read and understand it resulting in reaching a greater audience.
Although I though your argument was to the point and clearly laid out I think could benefit from adding the reason as to why there is an increase on overfishing into your introductory paragraph. The human population is experiencing exponential growth in the las decade which has led to over exploitation of marine life in order to support the demand for food. Evidence for this is the fact that fishing fleets have also gotten 2-3 times larger (Atalah, 2010) and modern techniques to withstand the amount of harvesting, transport and storage has increased alongside the fish exploitation trend. The United Nations food and agriculture organization (FAO) have stated that 52% of the world fish stocks are fully exploited and 25% ae either depleted or over exploited. The trend of fishery stock collapse is only going to increase with time, a study shows 29% of fish seafood species have collapsed and predicted to completely collapse by 2048 (Atalah, 2010) unless immediately dealt with. Your statements were also quite generalized in the sense of the whole ocean was effected the same way. The collapse of stocks was not effecting the entire ocean, each regional area was affected relative to other regions. For example over exploitation was specifically occurring in coastal and intertidal areas rather than open ocean ecosystems. An example of this is seen in intertidal limpets in different regions, like Hawaii and the canaries, have shown collapse and declines (Hawkins, 2000)
You could also explain and expand on the direct and indirect effects exploitation of fisheries can cause as the only one you had listed was that marine species preservation would rapidly decline. Direct effects can include physical disturbances by the fishing gear on the fish’s habitat. The ocean floor tends to be under serious attack and destruction in areas in which trawling is largely implemented. Trawling is when ships use machinery and nets to scrape across the seas bed in order to catch demersal species like Turbot, flounders and flat fish. The bed of the North Sea is trawled at least twice a year (Atalah, 2010) and with technology/machinery increase the gear used gets heavier and larger each time, meaning an increase in habitat destruction. The consequences of this are more than what meets the eye. Not only does trawling cause extreme sea bed destruction but it can lead to the extinction and extreme decline of species living in the North Sea. Molluscs and echinoderms species in the north sea have rapidly declined which, due to the use of trawling, which has led to more negative effects as they had important functional roles in the biogeochemical cycle in the ocean, it’s like a domino effect.
Indirect effects are essentially the same as the consequences mentioned before in which the main direct effect can lead off into even more damaging effects. There are two different types of indirect effect. Firstly is ghost fishing, this effect occurs when fishing fleets leave behind nets. These nets are almost invisible in the water and they sit on the coral reefs or float in the open sea. This leads to several marine species like sea turtles getting tangled up and their movement is restricted so the sea creature dies of starvation, cuts form the ropes when trying to struggle out and suffocation for ones who need air. The other is trophic cascading effects which is when there is a predator at the top of the food chain which is removed due to overfishing which shifts the entire food web and effects every level under it, As well as the obvious effect of the food web competition. This would come about when the top predator is removed as species will fight to fill its place altering many different marine food webs.
In terms of the government’s attempts to decrease fishing exploitation you mentioned protection zones such as setting up marine protected areas (MPA’s) but could have expanded in talking about the implemented fishing quotas. Sustainable fisheries were out into place in order to restore populations or endangered species and establish fishing quotas so that certain fisheries can only fish at certain times and take so much fish. As well as establishing specific areas that fisheries are allowed to fish in as this in theory would level out the amounts taken from different areas, so that not everyone is overfishing in the same region, like a grid on the ocean. However I agree with you when you said that “fishing regulations are difficult to impose” as it’s hard to control, manage and observe all the boats and fisheries and make sure they take a fair amount of fish, at the right time and in the right area. As well as that conflicts can arise from it as other areas will be more plentiful in different types of fish so it can be unfair. I recommend reading this article on the method of not using a grid format but looking at alternative ways to decrease overfishing:

Atalah, Javier (2010): Over exploitation. Available from [accessed on 9-10-2015]
Hawkins, S.J., Corte-Real, H.B.S.M., Pannacciulli, F.G., Weber, L.C. & Bishop, J.D.D. (2000) Thoughts on the ecology and evolution of the intertidal biota of the Azores and other Atlantic Islands. Hydrobiologia 440: 3–17

About the author

Environmental science, aquatic ecology student at the college at Brockport. PWSAC hatchery technician, research foundation research assistant