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Pacific herring and fisheries management in Canada: A new era or repeated history?
... Following federal fisheries management conflict with several First Nations (e.g. Mandamin 2014, Manson 2015, Fox et al. 2016), a signaled shift towards co-management and development of a national Sustainable Fisheries Framework (Fisheries and Oceans Canada 2016) represents a rare opportunity for change. However, it remains to be demonstrated how and if broader socioecological perspectives on forage fish, coastal ecosystem considerations (including nearshore, intertidal, and terrestrial ecosystems), and local and Indigenous knowledge will be meaningfully incorporated. ...
As intermediaries between the bottom and top of food webs, forage fish fuel a diversity of coastal consumers and are of socioecological importance throughout the world’s oceans. Many forage fish are migratory, but despite their recognized importance, relatively little is known about their role in providing spatial subsidies, which are the movements of energy, material, and organisms across ecosystems. Until recently, spatial subsidies associated with Pacific herring Clupea pallasii, a dominant migratory forage fish that spawns in subtidal and intertidal zones, received little scrutiny. Building on research that traced links between herring spawns and coastal ecosystems, we used stable isotopes of carbon (δ¹³C) and nitrogen (δ¹⁵N) to assess whether herring spawning events influenced isotopic signatures of 10 macrophyte and invertebrate species across beaches where spawning did or did not occur. Overall, species collected from spawning beaches had significantly greater δ¹⁵N levels (general linear mixed model parameter estimate = 1.58 ± 0.17 SE, F1,370 = 83.77, p < 0.001); no significant effects were detected for δ¹³C (parameter estimate = 0.03 ± 0.23 SE, F1,343 = 0.01, p = 0.914). In terms of total nitrogen, macrophytes from spawning beaches had significantly elevated concentrations (parameter estimate = 5.03 ± 0.94 SE, F1,180 = 28.71, p < 0.001). Using directional statistics, mean angles of isotopic change differed significantly between species collected from spawning and non-spawning beaches (Watson-Williams F-test; F1,48 = 10.44, p = 0.002). Our study identifies multiple species as recipients of herring-derived nutrients at spawning events, providing additional evidence of the broad ecological influence of Pacific herring.
The great “northern” cod (Gadus morhua) stock, formerly among the world’s largest and the icon for depletion and supposed nonrecovery of marine fishes, is making a major comeback after nearly two decades of attrition and fishery moratorium. Using acoustic-trawl surveys of the main prespawning and spawning components of the stock, we show that biomass has increased from tens of thousands of tonnes to >200 thousand tonnes within the last decade. The increase was signalled by massive schooling behaviour in late winter first observed in 2008 in the southern range of the stock (Bonavista Corridor) after an absence for 15 years, perhaps spurred by immigration. Increases in size composition and fish condition and apparent declines in mortality followed, leading to growth rates approaching 30% per annum. In the spring of 2015, large increases in cod abundance and size composition were observed for the first time since the moratorium in the more northerly spawning groups of this stock complex. The cod rebound has paralleled increases in the abundance of capelin (Mallotus villosus), whose abundance declined rapidly in the cold early 1990s but has recently increased during a period of warm ocean temperatures. With continued growth in the capelin stock and frugal management (low fishing mortality), this stock could rebuild, perhaps within less than a decade, to historical levels of sustainable yield. More generally, if this stock can recover, the potential exists for recovery of many other depleted stocks worldwide.
Government-administered science in Canada, and its potential for bureaucratic and political interference, merits examination in the wake of the biological and socioeconomic catastrophes associated with recent fishery collapses. We cite specific research on Atlantic cod (Gadus morhua) and Pacific salmon (Oncorhynchus spp.) habitat to illustrate how nonscience influences can interfere with the dissemination of scientific information and the conduct of science in the Canadian Department of Fisheries and Oceans. The present framework for linking fisheries science with fisheries management has permitted, intentionally or unintentionally, a suppression of scientific uncertainty and a failure to document comprehensively legitimate differences in scientific opinion. We suggest that the conservation of natural resources is not facilitated by science integrated within a political body. The formation of a politically independent organization of fisheries scientists, or some such reorganization of the link between scientific research and the management of natural resources, merits serious and open debate.
Overfishing of large-bodied benthic fishes and their subsequent population collapses on the Scotian Shelf of Canada's east coast and elsewhere resulted in restructuring of entire food webs now dominated by planktivorous, forage fish species and macroinvertebrates. Despite the imposition of strict management measures in force since the early 1990s, the Scotian Shelf ecosystem has not reverted back to its former structure. Here we provide evidence of the transient nature of this ecosystem and its current return path towards benthic fish species domination. The prolonged duration of the altered food web, and its current recovery, was and is being governed by the oscillatory, runaway consumption dynamics of the forage fish complex. These erupting forage species, which reached biomass levels 900% greater than those prevalent during the pre-collapse years of large benthic predators, are now in decline, having outstripped their zooplankton food supply. This dampening, and the associated reduction in the intensity of predation, was accompanied by lagged increases in species abundances at both lower and higher trophic levels, first witnessed in zooplankton and then in large-bodied predators, all consistent with a return towards the earlier ecosystem structure. We conclude that the reversibility of perturbed ecosystems can occur and that this bodes well for other collapsed fisheries.
The rarity or absence of highly interactive species leaves a functional void that can trigger linked changes leading to degraded or simplified ecosystems. A preliminary analysis indicates a relatively high frequency of such interactive species among endangered mammals. Rapid environmental change is likely to increase the interactivity of some species and reduce that of others over relatively short intervals. The current implementation of environmental policies and laws, such as the U.S. Endangered Species Act, generally ignores interspecific effects; recovery goals are autecological, short term, and numerically and spatially minimalistic. Moreover, by failing to account for interspecific interactions, recovery objectives are becoming indefensible in light of increasing knowledge from community ecology. Using the sea otter ( Enhydra lutris ) and wolf ( Canis lupus ) as examples, we argue that conservation plans should call for recovery or repatriation of such interactive species at ecologically effective densities in as many places as are currently realistic. It will be prudent and beneficial to estimate ecologically effective densities where there is disagreement among experts and interested parties about the desirability of restoring an interactive species to a particular region and to a particular density.
Memorandum for the Minister, Re-opening Strategy for Three Major Herring Stock Areas
- Oceans Fisheries
- Canada
Fisheries and Oceans Canada, 2013. Memorandum for the Minister, Re-opening
Strategy for Three Major Herring Stock Areas, 2013-502-00354.
Letter to Integrated Herring Harvest Planning Committee Members and Other Interested Parties Regarding
- Oceans Fisheries
- Canada
Fisheries and Oceans Canada, 2015. Letter to Integrated Herring Harvest Planning
Committee Members and Other Interested Parties Regarding 2015/2016 Pacific
Herring Harvest Planning.
Federal Court, between the Ahousaht, Ehattesaht, Hesquiaht, Mowachaht emuchalaht and Tla-o-qui-aht Indian Bands and Nations Contents lists available at ScienceDirect Ocean & Coastal Management j o u r n a l h o m e p a g e : w w w . e l s e v i e r
- L S Mandamin
Mandamin, L.S., 2014. Federal Court, between the Ahousaht, Ehattesaht, Hesquiaht,
Mowachaht emuchalaht and Tla-o-qui-aht Indian Bands and Nations
Contents lists available at ScienceDirect
Ocean & Coastal Management
j o u r n a l h o m e p a g e : w w w. e l s e v i e r. c o m / l o c a t e / o ce c o a m a n
Ocean & Coastal Management 125 (2016) 47e48
Federal Court, between the Council of the Haida Nation and Peter Lantin, Suing on Behalf of All Citizens of the Haida Nation (Applicants) and Minister of Fisheries and Oceans (Respondent). Docket T-73e15, Citation
- M D Manson
Manson, M.D., 2015. Federal Court, between the Council of the Haida Nation and
Peter Lantin, Suing on Behalf of All Citizens of the Haida Nation (Applicants)
and Minister of Fisheries and Oceans (Respondent). Docket T-73e15, Citation
2015 FC 290.