Lyall Bellquist

• PhD
• Researcher at The Nature Conservancy, San Diego

The Silky Shark (Carcharhinus falciformis) is highly vulnerable to population decline, yet leads shark bycatch in some of the world’s largest tuna fisheries. As such, this species provides an appropriate case study for regional fisheries management organizations—exemplified by the Inter-American Tropical Tuna Commission—to develop conceptual popula...

Climate variability and change are having dramatic effects on marine species, fisheries, and fishing communities. Climate perturbations elicit fishery management responses intended to mitigate negative effects, but the responses often do not account for the complexity of fisheries systems, leading to unintended consequences. However, including more...

Data-limited fisheries frequently lack age-structure data and instead rely on length-based management and assessment methods. However, the performance of such length-based methods and control rules are often poorly understood when confronted with varying life-history characteristics. In this study, we used Length-Based Spawning Potential Ratio (LBS...

Spawning aggregation-based fisheries are notorious for booms and busts driven by aggregation discovery and subsequent fishing-induced collapse. However, environment-driven sporadic recruitment in some since-protected populations has delayed recovery, suggesting recruitment-limitation may be a key driver of their population dynamics and fishery reco...

Spawning aggregation-based fisheries are notorious for booms and busts driven by aggregation discovery and subsequent fishing-induced collapse. However, environment-driven sporadic recruitment in some since-protected populations has delayed recovery, suggesting recruitment-limitation may be a key driver of their population dynamics and fishery reco...

Collaborative fisheries research programs engage stakeholders in data collection efforts, often with the benefit of increasing transparency about the status and management of natural resources. These programs are particularly important in marine systems, where management of recreational and commercial fisheries have historically been contentious. O...

This study reports on the fine-scale movements of swordfish (Xiphias gladius) tagged off of the Antofagasta region of northern Chile, where harpoon fishing operations date back more than seven millenia. The study was conducted within a highly productive swordfish foraging area where movements and habitat use remain poorly characterized. Swordfish w...

From fishers to farmers, people across the planet who rely directly upon natural resources for their livelihoods and well-being face extensive impacts from climate change. However, local- and regional-scale impacts and associated risks can vary geographically, and the implications for development of adaptation pathways that will be most effective f...

A variety of criteria may influence the efficacy of networks of marine protected areas (MPA) designed to enhance biodiversity conservation and provide fisheries benefits. Meta‐analyses have evaluated the influence of MPA attributes on abundance, biomass, and size structure of harvested species, reporting that MPA size, age, depth, and connectivity...

The fisheries history of the Giant Sea Bass, Stereolepis gigas (Telostei: Polyprionidae), is closely linked to its spatial ecology. Its overharvest is directly associated with formation of spatially distinct spawning aggregations during summer, while its subsequent recovery is hypothesized to be the result of spatially explicit gear restrictions. U...

Over one-third of elasmobranch fishes (sharks, rays, and skates) are threatened with extinction, mostly due to overfishing, habitat loss, and habitat degradation. Understanding the daily and seasonal movement patterns of these species can inform when and where populations are most susceptible to these threats, but these data are often lacking for n...

Aggregation-based fisheries are notorious for booms and busts driven by aggregation discovery and subsequent fishing-induced collapse. However, environment-driven sporadic recruitment in some since-protected populations has delayed recovery, suggesting recruitment-limitation may be a key driver of their population dynamics and fishery recovery pote...

Fisheries can adversely affect threatened bycatch species and vulnerable marine ecosystems (VMEs). Thresholds are unique amongst bycatch management methods in providing flexibility in individual participants' approaches to avoid exceeding limits, and particularly for individual vessel quotas , in incentivizing the innovation of effective and commer...

From fishers to farmers, people across the planet who rely directly upon natural resources for their livelihoods and well-being face extensive impacts from climate change. However, local- and regional-scale impacts and associated risks can vary geographically, and the implications for development of adaptation pathways that will be most effective f...

The status of federally managed fisheries in the United States is well monitored, but the condition of other marine fisheries, whether state‐managed, territory‐managed or unmanaged, is less understood and often unknown. We used expert surveys to characterize the management systems of non‐federally managed fisheries in US coastal marine states and o...

Marine heatwaves are increasingly affecting marine ecosystems, with cascading impacts on coastal economies, communities, and food systems. Studies of heatwaves provide crucial insights into potential ecosystem shifts under future climate change and put fisheries social-ecological systems through “stress tests” that expose both vulnerabilities and r...

Data-limited fisheries present significant challenges to fisheries management around the world. Landings data represent the simplest and most common source of fishery information, but length data of harvested species can offer particularly useful insight into the strength of fishing pressure and the status of stocks. However, unbiased length data c...

California recreational anglers have recently started using specific deep-drop tackle to target swordfish (Xiphius gladius) below the thermocline during the daytime. Increased rod-and-reel fishing effort stems from promising experimental fishing trials of a recently approved commercial gear type off California (deep-set buoy gear), along with the w...

Experimental fishing is a powerful tool to support adaptive management by exploring. innovative fisheries practices, scientific approaches, and management actions. In the. United States, capacity and interest exist to use on-the-water experimentation to test. alternative ideas to meet the national standards of the Magnuson-Stevens Act and. promote...

California's commercial and recreational fisheries support vibrant coastal economies and communities. Maintaining healthy fishing communities into the future requires a detailed understanding of their past. The California Department of Fish and Wildlife (CDFW) has been monitoring statewide fisheries landings and participation since 1916 and release...

Barotrauma—injury induced by changes in pressure—is a widespread challenge for successfully releasing fishes following capture. We used acoustic telemetry to examine the long-term post-release survival and behaviour of four rockfish species (genus Sebastes) suffering from barotrauma following capture using recreational fishing techniques. We placed...

Commercial, recreational, and indigenous fisheries are critical to coastal economies and communities in the United States. For over three decades, the federal government has formally recognized the impact of fishery disasters via federal declarations. Despite these impacts, national syntheses of the dynamics, impacts, and causes of fishery disaster...

Globally, one quarter of shark and ray species are threatened with extinction due to overfishing. Effective conservation and management can facilitate population recoveries. However, these efforts depend on robust data on movement patterns and stock structure, which are lacking for many threatened species, including the Critically Endangered soupfi...

An unusually long period of warm-water temperatures occurred off southern California (USA) in 2014–2018, and the highest sea-surface temperature ever recorded in a 103-year span of continuous data collection occurred in August 2018. Poleward distributional shifts in the geographic range of hundreds of marine organisms worldwide have been documented...

Modernizing data systems to inform collaborative management is critical to adaptively managing fisheries in an era of climate change. In 2006, The Nature Conservancy of California purchased 13 federal groundfish permits in California with the objective of managing the fishing and reporting activities in a manner that protected sensitive habitats an...

Fishes caught from depth often suffer from barotrauma, which can result in high mortality rates (close to 100% for some species) when released at the surface. To mitigate for this, the recreational fishing community pro-actively developed several different types of descending devices designed to assist unwanted or prohibited fish back toward the bo...

Among abalone species that were once harvested along the California coastline, red abalone (Haliotis rufescens) supports the remaining recreational fishery. To support development of a red abalone fishery management plan, non‐governmental organizations have initiated expanded data collection and developed fishery management strategies. The latter i...

Voluntary collective agreements among fishermen can improve the environmental and economic performance of a fishery, particularly when local leadership, strong incentives, catch accountability, and operational support are in place. Rights-based fisheries, such as Individual Fishing Quota (IFQ) systems, incentivize fishermen to act collectively to r...

The California Commercial Passenger Fishing Vessel (CPFV) fleet is unique in scale of operation, extensive fishing history, and economic impacts. The basses (Paralabrax sp.), which represent a principal target for the CPFV fleet, recently gained more stringent size limits and bag limits. The goal of this study was to conduct a survey of CPFV captai...

California (USA) recreational fisheries are biologically and economically important, and depend heavily on demersal fish species, especially during winter and spring months. While many of these species have shown signs of population decline, the size-selective nature of fishing generally impacts population size structure before population declines...

In order to better assess the ecological importance of offshore petroleum platforms for economically important groundfishes, we quantified the degree of site fidelity of 100 platform-associated individuals representing 15 species at three offshore platforms in the Santa Barbara Channel by means of acoustic telemetry monitoring. Thirty percent of th...

The fishery for California groundfishes is managed using broad species complexes, although some non-groundfish species are managed similarly due to the perception of shared behavioral characteristics. This study integrates acoustic telemetry and a GIS to quantify movement patterns of one such species, the ocean whitefish (Caulolatilus princeps) in...