“Ocean acidification” (OA), a change in seawater chemistry driven by increased uptake of atmospheric CO2 by the oceans, has probably been the most-studied single topic in marine science in recent times. The majority of the literature on OA report negative effects of CO2 on organisms and conclude that OA will be detrimental to marine ecosystems. As is true across all of science...
To assess status of fish populations and the risks of overexploitation, management bodies compare fishing mortality rates and abundance estimates with reference points (RP). Generic, “data-poor” methods for estimating RP are garnering attention because they are faster and cheaper to implement than those based on extensive life history data. Yet data-poor RP are subject to many...
The spatio-temporal variation in sea-spawning whitefish (Coregonus lavaretus s. l.) larval densities and their sizes was analysed with the aim to suggest a useful sampling dimensioning in terms of number of replicates and to find an optimum time for sampling to minimize the sampling variance. We also investigated the potential to predict optimal sampling in advance based on air...
Society is moving towards a no-analogue climate that will fundamentally affect ocean ecosystems and the socio-economic activities that depend on them. Warming has led to displacements of various populations, calling for an adaptation of fisheries management plans and Species at Risk recovery strategies. Dissolved oxygen (DO) has declined, but its impacts on habitat are much less...
Trends towards a more participatory agenda in policy-relevant science imply that the roles and work tasks of scientists become more multifaceted. In Europe, the increased use of multiannual plans creates a need for fishery scientists to contribute with their expertise in a wide variety of situations. We identify and characterize four roles for scientists as developers, reviewers...
Using numerical models to project the state of marine ecosystems several decades into the future is commonly advocated, in particular for investigating the possible effects of climate change. Numerical models are useful to explore how ocean climate and other drivers may regulate the dynamics of marine ecosystems and constitute indispensable tools to test our conceptual...
This essay contrasts the inferences about the patterns of size-dependent mortality in larval fish based on the traditional catch-curve approach with that achieved through the vertical life table method in an application to data from coastal Newfoundland. Although both approaches reveal that the average mortality rates decline with increasing body size, the rate of decline...
Year-class strength of Barents Sea capelin has been monitored closely since the early 1970s and during this ∼45 years period three short periods of almost total recruitment failure leading to three stock collapses have been observed. These events triggered much attention since there was a large commercial fishery for capelin, but also because of observed ecosystem effects...
Plastic debris is now ubiquitous in the marine environment affecting a wide range of taxa, from microscopic zooplankton to large vertebrates. Its persistence and dispersal throughout marine ecosystems has meant that sensitivity toward the scale of threat is growing, particularly for species of conservation concern, such as marine turtles. Their use of a variety of habitats...
This study assesses the seabed pressure of towed fishing gears and models the physical impact (area and depth of seabed penetration) from trip-based information of vessel size, gear type, and catch. Traditionally fishing pressures are calculated top-down by making use of large-scale statistics such as logbook data. Here, we take a different approach starting from the gear itself...
An improved understanding of the physical interaction of towed demersal fishing gears with the seabed has been developed in recent years, and there is a clearer view of the underpinning mechanical processes that lead to the modification and alteration of the benthic environment. The physical impact of these gears on soft sediments can be classified broadly as being either...
Deep-sea fisheries operate globally throughout the world's oceans, chiefly targeting stocks on the upper and mid-continental slope and offshore seamounts. Major commercial fisheries occur, or have occurred, for species such as orange roughy, oreos, cardinalfish, grenadiers and alfonsino. Few deep fisheries have, however, been sustainable, with most deep-sea stocks having...
Understanding the impacts of fishing on the seabed is a basic requirement for ecosystem-based marine management. It is only recently that we have begun understanding how fisheries-driven perturbations affect ecosystem function, biodiversity, productivity, and resilience. Technical solutions aimed at minimizing seabed impacts are starting to appear, but their efficacy remains to...
The three northern hemisphere anguillid eel species experienced recruitment declines at similar times beginning in the 1970s and 1980s, but the exact causes of the declines have remained unclear. Attention focused on two categories of possible causes that included (i) anthropogenic impacts on eel growth habitats, such as dam construction, degradation and pollution of habitats...
This symposium issue of the ICES Journal of Marine Science contains 16 contributions from the second International Eels Symposium held during the American Fisheries Society (AFS) Annual Meeting (August 2014, Québec City, Canada). This symposium followed the first International Eels Symposium held in 2003, which emphasized the international scope of the Anguilla conservation...
The Japanese scallop (Patinopecten (Mizuhopecten) yessoensis) is an important commercial species in Funka Bay, Japan, where it is farmed using the hanging culture method. Our study was based on 6 years (from 2006 to 2011) of monthly in situ observations of scallop growth at Yakumo station. To produce a basic spatial distribution dataset, we developed an interpolation solution for...
Discarding of commercially important fish species in the bottom trawl fisheries in the northern Mediterranean Sea was investigated by soliciting the long-term recollections of fishers engaged or formerly engaged in such fisheries. The main aim of our investigation was to describe the prevalence of discarding and its evolution over the past 70 years using information gathered...
Preserving larger fish is often advocated as a conservation measure to help fish populations buffer environmental variation and fishing pressure. The rationale is that several size- and age-dependent reproductive traits confer a higher reproductive value to larger fish. The effects of variation in these reproductive traits on the dynamics of populations under various fishing...
Having valid information about the location and dynamics of biological processes is important for coastal management. In this context modelling, the pelagic drift of early life stages has been shown to be an important tool for understanding the spatial scale of population dynamics in marine systems. Often simulated particles are released in hypothetical quantities at assumed...
A gigantic light experiment is taking place in the Arctic. Climate change has led to substantial reductions in sea ice extent and thickness in the Arctic Ocean. Sea ice, particularly when snow covered, acts as a lid hindering light to reach the waters underneath. Less ice will therefore mean more light entering the water column, with profound effects on pelagic and benthic...
In this essay, I review nearly six decades of a career in marine science and fisheries considering scientific contributions, successes, failures, and changes in my field of practice. My body of work has been in plankton research to support fisheries assessments, and in ecosystems programme development and implementation. I describe my early studies on Pacific plankton...
In a typical age and growth study, multiple estimates of individual fish age are generated: by readers, methods, etc. These samples of paired data are evaluated with three complementary approaches: (i) tabulate or graph the data to illustrate patterns, (ii) calculate indices of precision to evaluate repeatability, and more recently, (iii) use tests of symmetry to evaluate bias...
Fish otoliths have provided biologists with a treasure-house of valuable life history information across levels of biological organization from individuals to ecosystems. Otoliths have long been used to provide the age and growth estimates which are basic data that underpin scientific fisheries and fisheries ecology. The traditional use of calcified tissues (CS) has been...
Atlantic cod (Gadus morhua) caught in recreational fisheries are commonly released, often with barotrauma after rapid decompression. Mouth-hooked, non-bleeding cod kept in a floating net pen showed mortalities ≥40% when angled from >50 m depth, likely because of cumulative stress from ongoing barotrauma and exposure to warm surface water. In a natural setting, however, cod have...
Dams are a major contributor to the historic decline and current low abundance of diadromous fish. We developed a population viability analysis to assess demographic effects of dams on diadromous fish within a river system and demonstrated an application of the model with Atlantic salmon in the Penobscot River, Maine. We used abundance and distribution of wild- and hatchery...