Nancy Shackell

Bedford Institute of Oceanography · Fisheries and Oceans Canada

We investigated conflicting perspectives over a transboundary species (Atlantic Halibut-Hippoglossus hippoglossus L.) assumed to be one population spanning the border separating the USA and Canada. In Canada, the fishery is certified as sustainable by the international Marine Stewardship Council (2013). In the USA, that same population is listed as...

Global scale forecasts of range shifts in response to global warming have provided vital insight into predicted species redistribution. We build on that insight by examining whether local warming will affect habitat on spatiotemporal scales relevant to regional agencies. We used generalized additive models to quantify the realized habitat of 46 tem...

Shackell, N. L., Bundy, A., Nye, J. A., and Link, J. S. 2012. Common large-scale responses to climate and fishing across Northwest Atlantic ecosystems. – ICES Journal of Marine Science, 69: 151–152. Investigating whether there were common biological responses to climate and fishing across seven Northwest Atlantic ecosystems, a minimum/maximum autoc...

Globally, overfishing large-bodied groundfish populations has resulted in substantial increases in their prey populations. Where it has been examined, the effects of overfishing have cascaded down the food chain. In an intensively fished area on the western Scotian Shelf, Northwest Atlantic, the biomass of prey species increased exponentially (doub...

We have learned much about the impacts of warming on the productivity and distribution of marine organisms, but less about the impact of warming combined with other environmental stressors, including oxygen depletion. Also, the combined impact of multiple environmental stressors requires evaluation at the scales most relevant to resource managers....

Unintended bycatch of depleted or vulnerable marine species is an unsolved conservation issue that undermines the sustainability of fisheries worldwide. In Canada, policy incentives to address bycatch of vulnerable species-at-risk have become more prominent in recent years. Yet bycatch risk has been difficult to quantify and mitigate, in part due t...

Knowledge of recruitment and its variability in marine fish populations contributes to sustainable fisheries but a full understanding remains elusive. An earlier study showed that haddock (Melanogrammus aeglefinus) stocks exhibited consistently higher variability and lower reproductive rates compared to cod (Gadus morhua) stocks in the geographic r...

Climate change is impacting virtually all marine life. Adaptation strategies will require a robust understanding of the risks to species and ecosystems and how those propagate to human societies. We develop a unified and spatially explicit index to comprehensively evaluate the climate risks to marine life. Under high emissions (SSP5-8.5), almost 90...

The abundance, distribution, and size of marine species are linked to temperature and nutrient regimes and are profoundly affected by humans through exploitation and climate change. Yet little is known about long-term historical links between ocean environmental changes and resource abundance to provide context for current and potential future tren...

There has been a proliferation of climate change vulnerability assessments of species, yet possibly due to their limited reproducibility, scalability, and interpretability, their operational use in applied decision-making remains paradoxically low. We use a newly developed Climate Risk Index for Biodiversity to evaluate the climate vulnerability an...

Environmental impacts on fisheries are pervasive, yet methods to account for them in stock assessments and management decisions vary in rigour and quality. The prevalence and efficacy of methods to account for environmental impacts are not well documented, limiting our ability to adequately respond to future environmental and climate changes for ad...

Climate change and biodiversity loss are twin crises that are driving global marine conservation efforts. However, if unaccounted for, climate change can undermine the efficacy of such efforts. Despite this, integration of climate change adaptation and resilience into spatial marine conservation and management has been limited in Canada and elsewhe...

Bycatch in commercial fisheries is a pressing conservation concern and has spurred global interest in adopting ecosystem-based management practices. To address such concerns, a thorough understanding of spatiotemporal relationships among bycatch species, their environment and fisheries is required. Here we used a generalized linear mixed model fram...

The theory of island biogeography (TIB) predicts that species richness in isolated areas is determined by the processes of colonization and extinction, and, in turn, governed by island size and isolation. Metacommunity models extend the TIB, predicting that both habitat and species interactions are important drivers of community vital rates and str...

Characterizing the nature of genetic differentiation among individuals and populations and its distribution across the genome is increasingly important to inform both conservation and management of exploited species. Atlantic Halibut (Hippoglossus hippoglossus) is an ecologically and commercially important fish species, yet knowledge of population...

Interactions between spatial dynamics and stock structure in marine fishes have largely focused on stocks in decline; stock structure is rarely re-visited for expanding species. Here, the spatial ecology of Atlantic halibut (Hippoglossus hippoglossus L.), managed as four stocks in the Northwest Atlantic, is reviewed. Halibut collapsed under high ex...

Social-ecological systems dependent on fisheries must be resilient or adapt to remain viable in the face of change. Here, we identified possible interventions (termed “adaptation options”) from published literature, aimed at supporting social or ecological resilience and/or aiding adaptation to changes induced by environmental or social stressors....

The United Nations Convention on Biological Diversity was established in 1993. Canada is a signatory nation that has adopted, and exceeded, the UN Aichi biodiversity target to protect 10% of coastal and marine areas through marine protected areas or “other effective area-based conservation measures” (OECMs) by 2020. However, the science of OECMs as...

Marine biota are redistributing at a rapid pace in response to climate change and shifting seascapes. While changes in fish populations and community structure threaten the sustainability of fisheries, our capacity to adapt by tracking and projecting marine species remains a challenge due to data discontinuities in biological observations, lack of...

Climate change is already affecting the forest sector, especially through extreme events such as wildfire. These effects are expected to continue and intensify, requiring greater efforts to implement adaptation measures. While no single road map exists to guide adaptation implementation, regional risk assessments in Canada have highlighted the need...

• Climate change is commonly associated with many species redistributions and the influence of other factors may be marginalized, especially in the rapidly warming Arctic. • The Barents Sea, a high latitude large marine ecosystem in the Northeast Atlantic has experienced above‐average temperatures since the mid‐2000s with divergent bottom temperatu...

Marine biota are redistributing at a rapid pace in response to climate change and shifting seascapes. While changes in fish populations and community structure threaten the sustainability of fisheries, our capacity to adapt by tracking and projecting marine species remains a challenge due to data discontinuities in biological observations, lack of...

Sea surface temperature (SST), salinity, and chlorophyll concentration (CHL) have changed in the US Northeast Shelf ecosystem over recent decades. The changes in these parameters were distinctly marked by change points around the year 2012 resulting in a 0.83°C increase in SST, a 0.3 PSU increase in salinity, and decrease in CHL in excess of 0.4 mg...

Marine biota is redistributing at a rapid pace in response to climate change and shifting seascapes. While changes in fish populations and community structure threaten the sustainability of fisheries, our capacity to adapt by tracking and projecting marine species remains a challenge due to data discontinuities in biological observations, lack of d...

Determining the importance of physical and biological drivers in shaping biodiversity in diverse ecosystems remains a global challenge. Advancements have been made towards this end in large marine ecosystems with several studies suggesting environmental forcing as the primary driver. However, both empirical and theoretical studies point to addition...

Climate change impacts on fisheries will undoubtedly have socioeconomic impacts on coastal communities and the seafood market. However, it is a challenge to integrate climate change information in a form that can be used efficiently by adaptation planners, policy makers, and fishery managers. In this study, we frame a climate change impact assessme...

2019. Growing degree-day influences growth rate and length of maturity of Northwest Atlantic halibut (Hippoglossus hippoglussus L.) across the southern stock domain. Abstract The NAFO divisions 3NOPs4VWX5Zc Atlantic halibut (Hippoglossus hippoglussus L.) stock is managed over a large spatial scale, spanning over 20° of longitude and 6° of latitude....

The Atlantic halibut (Hippoglossus hippoglossus) longline fishery is the second most valuable groundfish fishery in Atlantic Canada and received Marine Stewardship Council certification in 2013. The bottom longline fishery accounts for most halibut landings but incidentally catches nontargeted species (bycatch). Since 1998, Fisheries and Oceans Can...

The Atlantic halibut (Hippoglossus hippoglossus) longline fishery is the second most valuable groundfish fishery in Atlantic Canada and received Marine Stewardship Council certification in 2013. The bottom longline fishery accounts for most halibut landings but incidentally catches nontargeted species (bycatch). Since 1998, Fisheries and Oceans Can...

The trophic theory of island biogeography (TTIB) predicts that when predators are depleted, prey extinction rates decrease, leading to increases in prey alpha diversity and an increase in the slope of the species−area relationship (SAR). The TTIB has been tested and supported in a restricted set of systems at small spatial scales (0.25 m³ [reef pat...

Atlantic halibut (Hippo-glossus hippoglossus) is an increasingly valued commercial fish and its recent population growth has attracted the attention of fisheries scientists and managers both within and outside Canada. With renewed transnational interests in this species, fishery managers have relied on existing, but limited, ecological information...

In the early 1990s, the Northwest Atlantic Ocean underwent a fisheries-driven ecosystem shift. Today, the iconic cod (Gadus morhua) remains at low levels, while Atlantic halibut (Hippoglossus hippoglossus) has been increasing since the mid-2000s, concomitant with increasing interest from the fishing industry. Currently, our knowledge about halibut...

Spatial erosion of stock structure through local overfishing can lead to stock collapse because fish often prefer certain locations, and fisheries tend to focus on those locations. Fishery managers are challenged to maintain the integrity of the entire stock and require scientific approaches that provide them with sound advice. Here we propose a Ba...

Climate change and ocean acidification are the biggest non-fisheries threats to marine organisms across the global oceans. But where fish stocks are shared between different countries, these oceanographic changes can have consequences for governance regimes and extractive marine activities through changes in stock distribution, and the affording of...

According to density-dependent habitat selection theory, areas of high density can be indicative of high population productivity and have positive individual fitness consequences. Here, we explore six groundfish populations on the Scotian Shelf, Canada, where a decline in areas of high density beyond a certain threshold is associated with dispropor...

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 i...

Exploitation of living marine resources has resulted in major changes to populations of targeted species and functional groups of large-bodied species in the ocean. However, the effects of over-fishing and collapse of large top predators on the broad-scale biodiversity of oceanic ecosystems remains largely unexplored. Populations of the Atlantic co...

Data consisted of all commercial and non-commercial fish species sampled by the DFO annual summer (July) research bottom trawl surveys of the Scotian Shelf, Northwest Atlantic over a period of 41 years (1970-2010). The data were extracted from the Ocean Biogeographic Information System (OBIS) database. All analyses were done using R.

The Silences of the Archives, the Reknown of the Story. The Martin Guerre affair has been told many times since Jean de Coras and Guillaume Lesueur published their stories in 1561. It is in many ways a perfect intrigue with uncanny resemblance, persuasive deception and a surprizing end when the two Martin stood face to face, memory to memory, befor...

Resource managers need climate adaptation tools. We build on a popular tool, the climate change vulnerability assessment (CCVA), to identify vulnerable marine species. Only warming was considered, as warming is expected to have earlier impacts in the offshore than other climate drivers, and projections of other climate drivers are not well develope...

Marine Protected Areas (MPAs) are proposed to help conserve marine biodiversity and ecological integrity. There is much guidance on the optimal design of MPAs but once potential MPAs are identified there is little guidance on defining the final no-take boundaries. This is especially problematic in temperate zones where ecological boundaries are “fu...

The collapse of Northwest Atlantic groundfish in the early 1990s yielded a " natural experiment" within which to explore responses of ecosystems to a major perturbation. The " Pelagic Outburst" hypothesis was developed to explain an up to 900% increase in the abundance of small-bodied forage fishes and macroinvertebrates following this collapse and...

Globally, management decisions for recently established invertebrate fisheries are based on limited information. The negative consequences are being realized as now at least one-third of invertebrate fisheries are over-exploited, collapsed or closed. Management of a fishery should be based on abundance and productivity data. This information is oft...

Building on the preliminary Marine Protected Area (MPA) network analysis completed by Horsman et al. (2011), Fisheries and Oceans Canada (DFO) is leading a systematic approach to MPA network planning in the Scotian Shelf Bioregion. The major steps in the planning process are described in the National Framework for Canada’s Network of MPAs (Governme...

The spatial scale of similarity among fish communities is characteristically large in temperate marine systems: connectivity is enhanced by high rates of dispersal during the larval/juvenile stages and the increased mobility of large-bodied fish. A larger spatial scale of similarity (low beta diversity) is advantageous in heavily exploited systems...

Fisher, J. A. D., Frank, K. T., Kostylev, V. E., Shackell, N. L., Horsman, T., and Hannah, C. G. 2011. Evaluating a habitat template model's predictions of marine fish diversity on the Scotian Shelf and Bay of Fundy, Northwest Atlantic. – ICES Journal of Marine Science, 68: 2096–2105. Habitat template models that integrate physical, chemical, and b...

In southwestern Nova Scotia, haddock (Melanogrammus aeglefinus) spawning is centered on Browns Bank where the variability of a partial gyre influences the distribution of eggs and larvae. An unknown proportion of each year-class is advected northward to the Bay of Fundy. We examined the variability in length at age 2 as an index of retention during...

Age-specific, sex-specific survival rates for immature and mature capelin (Mallotus villosus) were estimated by linear least-squares models, using abundance data derived from annual acoustic/trawl research surveys conducted from 1982 to 1990 on the northern Grand Bank. Survival estimates for age 2 immature fish were comparable between sexes (annual...

The northwest Atlantic has had a notable history of living marine resource (LMR) exploitation. There have been calls for evaluating and improving approaches to manage those resources as stocks have undergone sequential depletion, with some dramatic instances of stock declines. The need for more holistic ecosystem-based approaches to manage LMRs has...

The northwest Atlantic has had a rich history of living marine resource exploitation. As stocks have undergone sequential depletion with some dramatic instances of stock declines in this region, there have been calls for evaluating and improving approaches to managing our use of these resources. As part of these calls and along with recognition tha...

Nye, J. A., Bundy, A., Shackell, N., Friedland, K. D., and Link, J. S. 2010. Coherent trends in contiguous survey time-series of major ecological and commercial fish species in the Gulf of Maine ecosystem. – ICES Journal of Marine Science, 67: 26–40. Fish are often delineated into distinct population or stock units that reflect human institutional...