Fishing about and about fishing

 

We need to take a rational approach to this emotive issue in fisheries management

The notion of permanently closing off major sections of fishing grounds has become recently a focus of hot disputes. This is another issue that stems from the deepening contradiction between demand for fish on one hand, and the finality of marine living resources and environmental constraints, on the other. During the last 150 years of growing world's population and growing fish market, it has been the increasing fishing capacity assisted by the rapid and accelerating development of technical sciences, technology, and engineering that has satisfied the demand.

Complexity. But in some areas, intensive fishing removed huge amounts of fish both, prey and predators, depleted stocks, and affected whole ecosystems. It was also amplifying the effect on fish stocks of various environmental shifts and fluctuations. Also pollution and destruction of coastal habitats play a major role in the deterioration of fishery resources. Modern fisheries management came to being and expanded its influence, but with results ranging from mediocre to miserable. Fisheries take place in a complex and dynamic system, and science has still a long way to go before it can analyze and understand all its workings. In many, if not most cases, even the best available science is still unable to provide fisheries managers with recommendations founded on a fully rational basis.

Controversies and confusion. This situation has become a mother of many controversies: fishing industry vs. government and regional management, small-scale vs. large scale fisheries, recreational vs. commercial fishermen, environmentalist groups vs. all above and fish farmers, and all above vs. all sorts of polluters and coastal and upstream developers. Each of these controversies seems to have its ups and downs. Nowadays, it is the issue of marine protected areas (MPA) that is causing a grand dispute, particularly in the USA, where the MPA became fashionable. In the heat of this dispute, in my opinion, protected areas in the sense of nature reserves are being confused with fishery management issues.

Even the staunchest stalwarts of commercial and recreational fisheries, cannot dispute the need for declaring certain marine and coastal habitats as "nature reserves", (whatever is the name used), only open for observation and scientific research. Especially, endangered coral reefs, sponge and inshore seagrass beds, and some other biogenic habitats produced by or consisting of living organisms should be protected, the same way any unique environment is protected on land. All the more that according to the study by Dr.Ben Halpern of the University of California, published in "Ecological Applications" of Feb., 2003 and based on 89 separate studies, fish biomass and diversity are higher on the average in MPAs than they had been before the reserves were established, or in the neighbourhood. This effect is independent of reserve size.

Nature reserves and no-take zones. But, MPAs represent only one of a whole catalogue of measures that can be applied to maintain fishing grounds at a sustainable level, and in many if not in most cases ­ not the best one. True nature reserves themselves have little to do with fisheries management, whether or not occurs incidental "spillover" of organisms, fish included, from the reserve to adjacent fishing grounds. Although, on average, creating a reserve appears to enhance biomass, and raise organism size and diversity, the effect of protected zones varies with the characteristics of area, species, and other conditions. As the Halpern study states, "It is important to remember, however, that these values have considerable variance and cannot be used to predict how a specific reserve will affect particular organisms or communities. And in the meantime, as T. J. Willis et al report (in Environmental Conservation (2003) Vol. 30, in a paper entitled: "Burdens of evidence and the benefits of marine reserves: putting Descartes before the horse?" that reviews over 200 papers on marine reserves), empirical scientific evidence about the reserves benefits is still meagre, in spite of a plethora of mathematical models and theorizing.

But, when managers and MPA promoters start believing or otherwise advocate permanent "fencing off" sections of fishing grounds as a fishery management measure - the confusion starts. In fact, closing any major section of fishing grounds to fishing doesn't lessen fishing pressure on the resource, if not accompanied by other effort-control measures. Otherwise, the same fleet is going to fish a smaller area, and increase the effort over an area unit. It takes in a separate ecological-economic study for each separate fishery to be managed. And this goes also for any sort of MPAs on fishing grounds. As Mark Powell wrote on the FISHFOLK discussion list: "Of course there will be higher catch rates, bigger fish, etc. just outside the "no-fishing-zone" (NFZ) boundaries, but the key unanswered question remains: Will the loss of the potential yield, or recreation, not taken from the NFZ be offset by higher yields, or recreation, within the entire ecosystem as compared to the yield, or recreation, that could have been obtained with conventional measures such as closures to particular types of fishing gear, closed seasons followed by open ones, or restrictions on the species or size of fish that may be harvested?"

 

The pollution factor. But closing areas only to fishing doesn't make yet a marine nature reserve. Such area must be also protected against any sort of pollution and other habitat-wrecking human activities. These don't have to be direct. Upstream pollution flowing down streams and rivers do havoc with inshore habitats. There're various ways to handle such effects. For example, according to reports from Australia, revival of natural filtration mechanisms by fencing streams' and rivers' sides and regrowing even narrow strips of riparian vegetation, especially where small gullies are also fenced, can remove up to 90% of agricultural chemicals.

One thing seems to be clear: nature reserves is one thing and fishing grounds management ­ quite another.