That ever-reliable settler of internet arguments, Wikipedia, defines ecosystem-based management as “an environmental management approach that recognizes the full array of interactions within an ecosystem.” At heart, this type of management is supposed to keep all the cogs of an ecosystem moving so we can continue to use the natural resources provided by it at a sustainable rate. The key difficulty with ecosystem-based management is that it requires very precise knowledge of just how all the species involved interact, which in turn requires a lot of investment in research. However, in the push to meet this lofty goal in natural resource management, it seems that some have taken to interpreting ecosystem-based approaches not as a way to keep the ecosystem functioning and providing resources, but as a way to manipulate it to favor our favorite resources. In the world of fisheries management there have been a few recent developments that throw into question what kind of “ideal” ecosystem managers are going for.
When looking at these three management stories, it’s important to remember the concept of shifting baselines. Essentially, the longer ecosystems (in this case marine) are impacted by humans, the more their impacted state becomes considered “normal” and the bar is gradually lowered for what constitutes a “healthy” ecosystem. This appears to be happening in Florida waters, where the recovery of the critically-endangered Goliath grouper is leading to calls to cull the big fish before they start cutting into the population of spiny lobsters. Never mind that research shows that these groupers eat mid-sized predatory fish that eat lobsters (therefore indirectly helping the lobster stock), or that the lobster population did not change significantly in response to the crash of grouper numbers (suggesting that the groupers have no direct predatory effect on the crustaceans), or that Goliath groupers may potentially be able to help out with the lionfish problem. They’re a large predatory fish that is increasing in numbers, therefore they must be throwing the ecosystem off balance. This is because Florida’s natural marine ecosystem, which in its less-impacted state included plenty of Goliaths, is something that many Florida fishermen haven’t seen in a while.
This being Ya Like Dags?, you knew this was going in a dogfish-related direction eventually. Conservative management policies were put in place to avert a dogfish stock collapse in the late 1990s and the stock was declared rebuilt in 2010. Since then, quotas have consistently been bumped up by the New England and Mid-Atlantic Fishery Management Councils and this year the fishery actually became the second shark fishery ever to be certified as sustainable by the Marine Stewardship Council. The latest round of quota increases, proposed by the MAFMC, would bring the annual quota up to 40.8 million pounds, and increase the daily trip limit to 4,000 pounds. To put this in perspective, this is less than 20 million pounds under the quota that caused the dogfish population to show signs of overfishing in the ’90s. Interestingly, this increase isn’t supported by some dogfishermen, who argue that an increased quota without the processing facilities to support it will just flood the market and drive the price of dogfish down. However, these fishermen are being countered by fishermen from outside the dogfish fishery, who support the increase on the logic that anything that hurts the dogfish population will help the population of their target species. The push for increased quota in this case is less about the rational arguments for increasing fishery efficiency and more about culling dogfish in the hopes that this will allow the “right” fish to recover.
Perhaps the most egregious example is a story broken by Dave earlier this month. In the NEFMC’s annual meeting summary, the Groundfish Advisory Panel recommends, among other relatively reasonable things, that the council needs to “find a legal way to kill more elasmobranchs.” Wow. Even if Dave’s interpretation is correct and this is meant to reference dogfishes and skates, this is tantamount to declaring a cull against an entire group of species. If this were simply calling for an increase in bycatch allowance, I would think it would be phrased as such. With this wide-open and frankly creepy wording, this recommendation could refer to any elasmobranch, even protected species such as a sand tigers and great whites. This is definitely one of the more worrisome things I’ve seen in a fishery management document, and it deserves all the scrutiny it can get.
All of these incidents point to a misunderstanding of the very nature of ecosystem-based management. In these cases managers appear to be taking a “reduce this, then that will increase” approach, in which certain “chosen” species are carefully managed while their potential competitors and predators are given a “kill ’em all” treatment. While there is some evidence that overfishing may have unbalanced the relationships between some species, those relationships are still too poorly understood to start picking winners and losers. That isn’t ecosystem-based management, it’s ecosystem manipulation.
The mighty cod stocks that helped drive the settlement of the Northeastern United States didn’t exist in a vacuum. They were supported by and supported an entire ecosystem that included herring, copepods, other groundfish, dogfish, large sharks, seals, and everything else with an ecological connection to the area. A healthy fish stock is shaped as much by its competitors and predators as it is by its prey. This is why single-species management has had such a mixed record of success. If we as scientists, fishermen, and managers are serious about ecosystem-based management, we need to be serious about the importance of every part of that ecosystem, not try to game it to favor a handful of species.