Sunday, 20 of May of 2012

Tag » Dr. Ray Hilborn

How Well, and How Poorly, We Harvest Ocean Life

Written by Cornelia Dean | Science Writer
 
Overfishing: What Everyone Needs to Know. Ray Hilborn, with Ulrike Hilborn.
To hear some other people tell it, many depleted stocks are recovering nicely.

Ray Hilborn, a fisheries scientist at the University of Washington, wades into this disagreement in his new book and comes out with a lucid explication of a highly tangled issue.

Each argument, he concludes, has some truth on its side. “It depends on where you look,” he writes. “You can paint horror story after horror story if you want. You can paint success after success.”

He navigates the path between horror and success through scores of questions and answers, nearly all of which demonstrate how difficult it is to sort this issue out.

Take the most basic question: What is overfishing? There are several answers, the book tells us. There is “yield overfishing,” in which people take so many fish that they leave too few to spawn or catch too many fish before they are grown. Then there is “economic overfishing,” in which economic benefits are less than they could be. If too many boats chase too few fish, for example, the struggle to make a good catch leads to overspending on boats, fuel and so on.

(There is also “ecological overfishing,” but that is something we must live with as long as we want to eat fish, Dr. Hilborn says. Fishing by definition alters the marine environment.)

Dr. Hilborn tells us of fisheries that succeed — like the halibut industry in Alaska — and fish stocks managed into difficulty, and then out again, like the pollock of the Bering Sea.

And he gets into the issue of trawling, in which boats drop weighted nets to the bottom and drag them along, scraping up everything in their path. Critics liken trawling to harvesting timber by clear-cutting. For Dr. Hilborn, this analogy is not always apt, since in some areas the creatures rapidly repopulate the ocean floor.

Some countries do well by their fish, he writes, but with one exception they are relatively small: New Zealand, Iceland and Norway. The exception? The United States.

The true lesson of this book is that fisheries science is complicated; that the management of any given species must be considered in terms of its ecosystem; that fishing for one species alters the food web as a whole — and that sometimes there is not enough data to make good recommendations.

 
Read the full book review on The New York Times.
 

Conservation in the Anthropocene: A Breakthrough Journal Debate

In their Breakthrough Journal essay, “Conservation in the Anthropocene,” Peter Kareiva, Michelle Marvier, and Robert Lalasz showed that conservation is losing the war to protect nature despite winning the battle to create parks and game preserves. While the number of protected areas has risen, species in wild places have fallen. Conservationists must shed their 19th Century vision of pristine nature, the authors wrote, and seek a new vision, one of “a planet in which nature exists amidst a wide variety of modern, human landscapes.”

In a new Breakthrough debate, a host of passionate 21st Century conservationists, including Kierán SucklingPaul RobbinsRay HilbornLisa Hayward, and Barbara Martinez, face off with the authors over the resilience of nature, corporate partners, and the state of conservation today.

Of particular interest is the commentary submitted by Professor Ray Hilborn. You can read his response below, or click here to see Breakthrough Journal’s full debate.

 


MARINE PARKS ARE FISHY

Ray Hilborn

By Ray Hilborn

In “Conservation in the Anthropocene,” Peter Kareiva, Robert Lalasz, and Michelle Marvier argue that conservation needs to move beyond parks and protected areas. They stress that ecosystems are generally resilient to perturbation, and rather than being irreparably damaged by the slightest anthropogenic impact, ecosystems can both support biodiversity and produce sustainable goods and services. While their arguments and examples are drawn from terrestrial ecosystems, much of their article is relevant to marine ecosystems, my field of study.

Marine ecosystems are the new frontier for conservation. And much of the funding for new scientific work has been directed towards the establishment of protected areas. It’s important to note that while marine and terrestrial ecosystems share much in common, there are differences. One fundamental difference is the nature of human use. In terrestrial ecosystems, a dominant form of use is agriculture, which essentially rips out native ecosystems and replaces them with exotic species: crops, tree plantations, or grasses for grazing. Agriculture makes no pretense about preserving natural ecosystems.

In contrast, in marine ecosystems, we attempt to sustainably harvest the natural ecosystem. We leave the lower trophic levels—primary producers and most of their consumers—untouched, and exploit only the higher trophic levels. This has profound consequences. It means that even if the dreams of protecting 10 percent of the world’s ocean, as set out in the 1992 Convention on Biodiversity, were to come true, most marine biodiversity will remain outside the boundaries. The struggle to maintain biodiversity is in the total anthropocene ocean; it will never be achieved through protected areas.

The marine conservation movement has been slow to grasp this. Similarly, it has failed to see that closing areas to fishing does not eliminate fishing pressure, it simply moves it. When an area is closed, fishing efforts concentrate outside protected areas. Consequently, simple comparisons of abundance inside and outside of reserves as a measure of “success” are meaningless. The salient question to ask is what happens to the total abundance.

One study sought to answer this question by tracking trends in abundance inside and outside of a set of reserves established in the California Channel Islands.1 Of the species targeted by commercial and recreational fishing, abundance went up inside reserves and down on the outside. Since 80 percent of the habitat is outside of the reserves, the data suggest that the total abundance of the targeted fish species actually declined. The gains inside were more than offset by the decreases on the outside.

In the case of the Channel Islands reserves, the creation of a protected area had a negative impact on abundance. In many other cases, protected areas have little to no impact. Two of the most heralded successes of the marine conservation movement have been the establishment of large protected areas in the Northwestern Hawaiian Islands, and the western Pacific US territories. If the measure of success is the amount of area proclaimed as protected, these are significant achievements. But if the objective is effective protection against real threats, the achievement is less because there was little, if any, human impact in those areas before protection.

There are many threats to marine ecosystems, including oil spills, exotic species, runoff from terrestrial sources, illegal fishing, excessive legal fishing, ocean acidification, and global warming. The marine parks movement does not recognize that most “protected areas” only “protect” from legal fishing, and not much else. Advocates argue that unfished ecosystems are more resilient to environmental perturbations such as exotic species, yet the same argument, if valid, must apply to areas outside of reserves. Since fishing pressure has been redirected to unprotected areas, those ecosystems ought to be more vulnerable to the same perturbation.

Kareiva et al. argue that the new conservation “requires conservation to embrace marginalized and demonized groups,” and perhaps no group has been so demonized by the environmental movement as fishermen. Terms like “roving bandits” and “rapers and pillagers” permeate the public discussion. But luckily this is changing. The new marine conservation movement recognizes that conserving biodiversity requires more than merely controlling fishing. Progressive NGOs are working with fishing groups rather than demonizing them, a transformation that has entered into in marine conservation debates that attempt to find new solutions to the environmental impacts of fishing.

Kareiva et al. close by stating, “Protecting biodiversity for its own sake has not worked. Protecting nature that is dynamic and resilient, that is in our midst rather than far away, and that sustains human communities—these are the ways forward now.” This is as true in the marine world as in the terrestrial. There is certainly a role for protected areas. But the bulk of marine biodiversity will always be in the dynamic areas outside of them, areas that must be sustainably managed as we go forward.

Ray Hilborn is a professor in the school of Aquatic and Fishery Sciences at the University of Washington.

1. Hamilton, S. L., J. E. Caselle, D. P. Malone, and M. H. Carr. 2010. “Incorporating biogeography into evaluation of the Channel Islands marine reserve network.” Proceedings of the National Academy of Sciences of the United States of America. www.pnas.org/cgi/doi/10.1073/pnas.0908091107.

 


Barbecued squid salad with snake beans and grapefruit

Serves 4

By Bill Granger

While fish can fall apart and be tricky to cook on a grill, prawns, langoustines, squid and other seafood are made for it. The punchy dressing and citrus give this squid salad a real kick.

2 green chillies, finely chopped
1 tsp sea salt
4 coriander root, rinsed well and roughly chopped
1 garlic clove
3 tbsp fish sauce
3 tbsp caster sugar
3 tbsp lime juice
Large handful picked, fresh mint leaves
Large handful fresh coriander leaves
300g/10oz snake beans or green beans, cut into 5cm lengths
2 pink grapefruit, peeled, cut into segments, pith and membrane removed
800g/1¾lb squid tubes, cleaned, cut into approx 6cm x 3cm pieces and scored on the inside
3 tbsp extra-virgin olive oil

Read the full recipe here.


Study: Rebuilding Global Fisheries

By Boris WormRay Hilborn et al.

After a long history of overexploitation, increasing efforts to restore marine ecosystems and rebuild fisheries are under way. Here, we analyze current trends from a fisheries and conservation perspective.

In 5 of 10 well-studied ecosystems, the average exploitation rate has recently declined and is now at or below the rate predicted to achieve maximum sustainable yield for seven systems.

Yet 63% of assessed fish stocks worldwide still require rebuilding, and even lower exploitation rates are needed to reverse the collapse of vulnerable species. Combined fisheries and conservation objectives can be achieved by merging diverse management actions, including catch restrictions, gear modification, and closed areas, depending on local context.

Impacts of international fleets and the lack of alternatives to fishing complicate prospects for rebuilding fisheries in many poorer regions, highlighting the need for a global perspective on rebuilding marine resources.

Read the whole study here.


Dr. Ray Hilborn: ‘The end of overfishing,’ what does it mean?

Ray Hilborn

Dr. Ray Hilborn examines the end of overfishing in the United States. He addresses what fisheries managers can control and what is in the realm of nature, beyond the reach of human management.

(SEAFOOD.COM NEWS) – Feb 7, 2011 – The following article from Ray Hilborn is in response to NMFS chief scientist Steve Murawski’s widely reported comments last month that US overfishing as ended. This is part of a continuing series of occasional articles on fisheries and conservation topics by Ray Hilborn, Professor at the School of Aquatic and Fishery Sciences, University of Washington, prepared for Seafood.com News.

Overfishing has ended in the U. S. said Professor Steve Murawski, former chief fishery scientist for NOAA on January 8th 2011.

Could this possibly be true?

With many fish stocks still at low abundance, subject to rebuilding plans and listed as overfished, how could he argue that overfishing has ended?

To understand the issue we first must begin with the distinction between “overfished” and “overfishing.” Overfished is a term used when the abundance of the stock is low enough that its sustainable yield is significantly reduced. Overfishing is when the percentage harvested is higher than required to provide long term maximum sustainable yield. So “overfished” is about abundance and “overfishing” is about the percentage we harvest.

What Murawski said is that the percentage harvested for all U. S. federally managed fish stocks is now within the range that would produce maximum sustainable yield.

We have stopped fishing too hard; but many fish stocks remain at low abundance.

Read the rest of the story on SavingSeaFood.org.


Rebuilding Global Fisheries [Video]

Ray Hilborn and Boris Worm comment on their findings in the Rebuilding Global Fisheries study:


Dr. Ray Hilborn Discusses the State of World Fisheries, and more…[Video]

“Doomsday will come to fishes across the world’s oceans by 2048.”  That was the startling implication of findings published in 2006 by marine ecologist Boris Worm of Dalhousie University in Halifax, Canada, and several colleagues.

The projection, published in a paper in Science magazine, was about the relationship between biodiversity and ecosystem services in the oceans, and concluded that the world’s oceans were in bad shape, in part because of overfishing.

But many fisheries scientists were appalled.  In fact, one prominent critic was Dr. Ray Hilborn, a professor in the School of Aquatic and Fishery Sciences, University of Washington, specializing in natural resource management and conservation.

Trained in quantitative techniques for determining the abundance of fish stocks, Hilborn and others  questioned the methods used in Worm’s global assessment.  The conflict continued a charged and long-simmering debate between marine ecologists and fisheries scientists about the status of the world’s ocean ecosystems.

Yet, less than a year later, as recounted in a Science magazine article entitled “Détante in the Fisheries War,” Hilborn and Worm began meeting on neutral ground to hammer out their differences. Working under the auspices of the National Center for Ecological Analysis and Synthesis(NCEAS) in Santa Barbara, California, Hilborn and Worm brought together some 20 scientists from their respective disciplines as well as dozens of graduate students.

Initial results from this collaboration were published in the July 31, 2009 issue of Science magazine: Rebuilding Global Fisheries.

A new series of videos posted on WorldNews provides a video account of the highlights of this ground-breaking research.  Three videos feature Dr. Hilborn on the state of the world’s fisheries. Another video, including interviews with both Hilborn and Boris Worm, highlights findings in the Rebuilding Global Fisheries study, and yet another video presents Dr. Hilborn’s remarks at a Science Advisory Team meeting of the Marine Life Protection Act Initiative in southern California, critiquing the state’s rigid size and spacing guidelines governing marine protected area placement in the Golden State.

The first three videos are posted below: