A recent study funded by the large-scale extraction industry claims that forage fish abundance doesn’t affect marine predator numbers…As anglers we know better.
Top photo courtesy John McMurray
Just when I thought I’d seen everything, I opened my email a few weeks ago to find a half-dozen messages about some new “ground-breaking” study funded by the same large scale/low-value fishing and fishmeal/fish-oil industry that, for the last two decades, has been trying to argue that taking hundreds of millions of pounds of forage fish out of the water has little-to-no impact on marine ecosystems. Gee… I wonder what they came up with.
Apparently, according to the paper, When does fishing forage species affect their predators? Hilborn et. al. 2017, forage fish (i.e. menhaden) abundance has minimal effect on predators (like, ahem, striped bass).
Frankly, I didn’t pay it much attention. Seemed like just more noise. What discredited the study almost right away for me was when Ray Hilborn, the primary author of the piece, claimed in a promotional video, (also funded by the industry), and in the paper itself, that predators like stripers aren’t affected by large-scale extraction of menhaden because they don’t eat the adults that the extraction industry targets. Uhm, really? Stripers only eat juvenile bunker? Even novice anglers understand the relationship between adult bunker aggregations and striped bass.
And really, I mean, come on man. I’d like to think that most people who understand fish and fishing just know that the basic conclusion in the paper isn’t true. It defies common sense… But somehow the authors of this paper have compiled enough data to make their case.
While it’s not easy to wade through all the information in this paper, I think that readers can understand that one can use data or interpret data in a way that supports any conclusion that one wants to reach. Given the funders of this paper, it’s easy to see how that may have happened here.
I don’t want to try and refute the paper’s conclusions from a technical standpoint. I’ll leave that to the pointy heads. In fact, given the letter recently submitted to the Atlantic States Marine Fisheries Commission’s (ASMFC) Atlantic Menhaden Management Board (correcting the record on forage fish and their predators) it looks like the Lenfest Forage Fish Task Force is already working on this.
What I’d like to do here is address the paper’s conclusions from an on-the-water perspective.
Regarding “Predator rate of increase is uncorrelated with forage fish abundance”
While it may go without saying, stripers, bluefish, tunas, billfish, etc., gotta eat. Pretty easy to understand that when more forage is available over a broader range, they are gonna do better.
People who spend time on the water know that when forage populations are healthy, there are more predators in the water. Often, abundant baitfish also means that predators have better body conditions (read “big and fat”).
The Hilborn paper makes the case that when forage stocks become depleted, the predators don’t just starve, they go to those limited core areas where there are still some bait fish. And so forage numbers shouldn’t matter to predators because even at low abundance levels, forage species will contract to areas where predators can still find them at relatively high densities.
But it’s pretty clear to me that a lot of predators, particularly those that depend on encountering concentrations of baitfish during their migrations (ahem, striped bass, again) don’t easily uproot themselves to track prey over distances. I mean, come on…. Do you really think stripers are going to turn around at New York and go back down to VA to feed on a contracted menhaden stock?
Yes, the paper talks about alternate baits (e.g. sandeels, bay anchovies, spearing, etc.), but is there any angler out there who thinks such “small” baits are as important to a striped bass’ diet as bunker? Having spent the better part of the last 20 years as a striped bass guide, I know that’s not true.
The paper does acknowledge that when a baitfish stock is abundant it expands, and so the predators have more fish to feed upon, over a wider range. That would certainly seem be more beneficial for the predators, even though the paper doesn’t draw that conclusion. But what it doesn’t mention is that this sort of expansion is beneficial for the greater public.
When an abundant and healthy forage fish resource expands its range and becomes more available to predators over a longer expanse of shoreline, the public has more opportunity to target and catch those predators.
Anglers in particular depend on that sort of forage distribution to be successful because it drives opportunity. Without a doubt, forage abundance drives time and area specific bites.
So taking a precautionary approach to managing forage stocks is, for that reason alone, important.
Yes, I understand that the paper’s conclusion is really that forage abundance doesn’t dictate overall predator abundance. And that there’s no tangible connection between baitfish abundance and recruitment. But I can’t help but believe even that is bull(expletive). If you don’t have enough to eat in the time and place where you happen to exist, then, well, you don’t procreate, or you don’t survive at all in the harsh marine environment. Certainly there are other studies that show that predators have lower survival and reproductive rates when forage populations decline.
Regardless, the sort of expanded stock that comes from “abundance” creates opportunity along a broader part of the coast, for a broader set of stakeholders. Despite the conclusions of this paper, managers need to understand this.
Regarding “Forage species are affected much more by environmental conditions than by fishing”
I won’t argue that environmental conditions don’t affect recruitment. Certainly, there can be favorable conditions that lead to more successful spawns, and better young of the year survival. We’ve seen this to be the case with a lot of species.
But with forage fish we’ve got to consider the scale of removals. In the case of menhaden in particular, we’re talking about hundreds of millions of pounds being removed on an annual basis from the ecosystem so it can be boiled down and reduced into product. It’s hard not to question the motives of anyone who thinks that’s insignificant.
In 2012, the ASMFC implemented the first ever constraining measures on the menhaden fleet, reducing catch by 20%. Industry’s party line has been that the reduction has had nothing to do with current abundance, and more to do with environmental conditions.
Perhaps environmental conditions for recruitment weren’t good… But if you leave a hundred million pounds of bunker in the water, well, there’s a hundred million pounds more bunker in the water, right?
It’s just intuitive that the stock expansion we’ve seen in the last few years, and the extraordinary amount of life that’s resulted (i.e. whales, striped bass, thresher sharks, etc.) are related to that reduction. To think otherwise seems pretty silly to me. Yet the techies, who still can’t put their finger on a “stock recruitment” relationship, have given that argument cover, and unfortunately there are managers who believe it as well.
In short, I will argue that forage species aren’t being affected by environmental conditions more than fishing. Both affect forage abundance… But fishing mortality is the only thing we CAN control. And so we should control it CAUTIOUSLY, as the Lenfest Report, which the paper takes great pains to refute, suggests.
Regarding “Previous analysis of forage fish impacts on predators ignored natural variability”
I don’t think previous analysis ignored “natural variability.”
The Lenfest Forage Fish Task Force reminds us that “…despite massive landings, even these apparently prolific [forage] fish are susceptible to population collapse when the effects of fishing and unfavorable environmental conditions act together,” and that “Accounting for such factors in devising management strategies can provide a buffer against overfishing during periods when populations are naturally low.”
As noted above, there is plenty of natural variability in forage fish abundance, primarily due to environmental conditions. Such wide swings in abundance should speak to precaution when managing forage harvest. Because when forage stocks are down, industrial fishing fleets in those areas of core abundance can still generally find them and knock the (expletive) out of them. When stocks are at natural lows, one would think that we’d want to leave enough in the water so that they have the ability to recover and become abundant again when environmental conditions allow.
Regarding “Predators often take small forage fish that are unaffected by fishing”
I am quite surprised that this conclusion was drawn, and I don’t know how on earth it passed peer-review. The data-sets appear to be so limited, I’m not sure they are useful in this context.
As I mentioned above, just about every fisherman in the Mid-Atlantic and New England knows that the trophy striped bass fishery thrives on adult bunker. It’s kinda funny that Hilborn uses that example.
Of course it’s not just striped bass/menhaden. Off shore a bit, billfish, tunas, makos, mahi, etc. eat the (expletive) out of adult chub, bullet and frigate mackerel. Bluefin tuna feast on schools of adult mackerel and Atlantic herring.
The assertion that predators eat mostly juvenile forage fish, instead of the adults, is a ridiculous one to most of us who spend time on the water.
Here’s why we should worry
Like I said before, the conclusions presented in the paper just seemed silly to me.
Basically it’s the same narrow, self-interest-focused argument the large-scale extraction industry has been using for decades. That massive extraction of forage fish has no effect… on anything. It’s the “we should be able to catch as much as we want” argument.
I had kinda thought that science and management had gotten beyond that. And that no manager would take such a paper seriously. But here we are, a few days away from a Management Board meeting, and on the agenda is a “Technical Review” of the paper.
This is not good…
As readers likely know, the Management Board is currently developing Amendment 3 to the Menhaden Fishery Management Plan, which will deal not only with state allocation but also with developing “ecosystem reference points.” What does that mean? Well, it’s really just a fancy way of saying that managers are finally considering managing menhaden with the entire ecosystem in mind, and with definitive emphasis on predator/prey relationships. In other words, they are giving full consideration to how many menhaden need to stay in the water so that predators have enough to eat. Given the fact that just about everything feeds on menhaden (whales, dolphins, ospreys, etc.) and given that we all know full well that menhaden drive striped bass abundance, and ultimately opportunity for anglers, in certain regions, this is something mangers should have done A LONG TIME AGO.
But now here we are, considering a paper that throws all of this out the window?
Without widely distributed bait concentrations, we simply don’t get the striped bass, bluefish, summer flounder, yellowfin, bluefin, mahi, billfish etc…
This is why you need to speak up, right now, and let the Commissioner in your state know that Hilborn’s paper is wrong… Forage fish abundance does matter! It matters to the fish we target, and it matters to us.