With the Bakun upwelling index almost 30 years old, a new publication by Mike Jacox explores two new indices derived from modeled vertical velocity: CUTI (coastal upwelling and transport index) and BEUTI (biologically effective upwelling and transport index). Mike has also provided a history of the upwelling indices focusing on where the indices agree and diverge. The publication is available in early view at JGR. Continue reading
By combining species distribution models from Hazen et al. 2013 with Global Fishing Watch data from Kroodsma et al. 2018, White et al. assesses overlap between tunas and sharks and Pacific fishing vessels. In addition, the manuscript assesses which species occur within North American Exclusive Economic Zones versus the open ocean requiring different approaches towards management.
There has been a good discussion on how scale effects overlap calculations for GFW data as well by Amaroso et al. and in the Kroodsma et al. response finding that “fished area” could be between 4% and 55% depending on the scale of calculation. Both articles provide a valid rationale for why their scale was chosen. The work here was conducted on a coarse spatial scale, so it is highly likely that overlap would decrease if finer resolution data were available, yet this scale is appropriate for the ecosystem footprint of much of the gear and the top predator models as well.
Many species of sharks and tunas are threatened by overexploitation, yet the degree of 24 overlap between industrial fisheries and pelagic fishes remains poorly understood. Using 25 satellite tracks from 1,007 industrial fishing vessels in conjunction with predictive habitat 26 models built using 2,406 electronic tags deployed on seven pelagic shark and tuna species, 27 we developed fishing effort maps by gear type across the Northeast Pacific Ocean and 28 assessed overlap with core habitats of pelagic fishes. We found that up to 35% of species’ 29 core habitats overlapped with industrial fishing effort and identified overlap hotspots 30 along the North American continental shelf, the equatorial Pacific, and Mexico’s 31 Exclusive Economic Zone. Our results indicate which species require international, high 32 seas conservation efforts for effective management (e.g., 90% of blue shark overlap and 33 48% of albacore tuna overlap occurs in international waters) and which may be effectively 34 managed by single nations (e.g., 75% of salmon shark overlap occurs in U.S. waters). 35 Vessels flagged to just 5 nations (Mexico, China, Taiwan, Japan, and the U.S.) account for 36 the vast majority (> 95%) of overlap with core habitats of our focal sharks and tunas on 37 the high seas. These results may inform ongoing, global negotiations over national fishing 38 rights and conservation priorities to achieve sustainability on the high seas.
T.D. White, F. Ferretti, D.A. Kroodsma, E.L. Hazen, A.B. Carlisle, K.L. Scales, S.J. Bograd, B.A. Block, in press. Predicted hotspots of overlap between highly migratory fishes and industrial fishing fleets in the Northeast Pacific. Science Advances. PDF
We are excited to have Stefan join the team, moving from his position in Bremen to our cooperative institute at UC Santa Cruz. During his PhD, Stefan used interdisciplinary methods to investigate the impacts of ongoing ocean warming and acidification on the marine ecosystem and human user groups in the sub-arctic Barents Sea. He developed and applied integrative ecological models that incorporate experimental and observational data on biological processes as well as the input of local stakeholder groups. The models allow to assess future shifts in marine fish stocks, food web-mediated impacts on marine mammals and seabirds, and changes in ecosystem functioning. They are used to develop feasible and fair strategies for ecosystem-based governance of climate change impacts in the marine realm. We are excited to have Stefan join the team and help develop similar models for the California Current!
When building an operational tool, building the ecological models is only part of the equation. Equally important is ensuring that we have operational tools and regular predictions for use in management. Welch et al. 2018 explore the operational-side of the EcoCast tool, including potential pitfalls and solutions towards decision making. The paper came out in early view in the Journal of Applied Ecology and there is a discussion on the steps involved in creating fisheries nowcasts in the Conversation.
Figure 1. The four stages of operationalizing a dynamic management tool (hollow fill) and internal components (grey fill). The framework is relevant to operationalizing tools at one point in time and does not encompass tool updates as new data become available.
Elucidating connections between ocean climate variability and change, and recruitment of juvenile fishes to adult populations, is critical for understanding variability in stock-recruit dynamics. Recruitment to adult rockfish populations in the California Current Ecosystem (CCE) is highly variable, leading to short and long-term changes in abundance, productivity, forage availability and potential fisheries yield. We used regional ocean model output, oceanographic data, and a 34-year time series of pelagic juvenile rockfish, to investigate the interaction between changes in CCE source waters as reflected by physical water mass properties and recruitment variability. Specifically, variability of spiciness on upper water isopycnals explains a substantial fraction of the variation in pelagic juvenile rockfish abundance. High rockfish abundances correspond to cooler, fresher waters with higher dissolved oxygen (i.e., minty) conditions, indicative of Pacific Subarctic Water. By contrast, years of low rockfish abundance are associated with warmer, more saline, and more oxygen deficient (i.e., spicy) conditions, reflecting waters of subtropical or equatorial origin. Transport and source waters in the CCE are key factors determining density-independent processes and subsequent recruitment to adult populations.
We are excited to have Megan join the team, moving from her position in UC San Diego to our cooperative institute at UC Santa Cruz. Her Ph.D. research investigated the effects of climate change on Pygoscelid penguins in the Southern Ocean by using underwater robots, animal-borne tags, habitat modeling approaches, IPCC global climate models, and multi-decadal satellite, weather and penguins observations. This research addressed multidisciplinary questions (climate change effects, changes in demography, predator-prey dynamics, interspecific competition) across multiple trophic levels and scales. As a post-doc at the Scripps Institution of Oceanography in the Coastal Observing Research and Development Center, she used autonomous robots in novel ways to study jellyfish distribution in a marine lake, a snapper spawning aggregation, and detect tagged and vocalizing animals. She is excited to join NOAA ERD where her work will continue to understand the bio-physical factors that drive species distributions and movements on multiple spatiotemporal scales with the ultimate goal of aiding in conservation and management.
Future Seas is a project exploring potential impacts of climate change on the swordfish, albacore, and Pacific sardine fisheries in the California Current System. A suite of dynamical, statistical, and conceptual models is being applied to explore future scenarios in an “end-to-end” framework spanning physical changes to socio-economic consequences, and to evaluate uncertainty associated with individual elements of the modeling framework.
How animal movement decisions interact with the distribution of resources to shape individual performance is a key question in ecology. However, links between spatial and behavioural ecology and fitness consequences are poorly understood because the outcomes of individual resource selection decisions, such as energy intake, are rarely measured. Download the PDF below to read more!
B. Abrahms, K.L. Scales, E.L. Hazen, S.J. Bograd, R.S. Schick, P.W. Robinson, D.P. Costa. 2018. Mesoscale activity facilitates energy gain in a top predator. Proceedings of the Royal Society B, 285: 20181101. DOI: 10.1098/rspb.2018.1101. PDF
Steph Brodie published a manuscript in Frontiers in Marine Science on how we can improve habitat models by including subsurface variables.
Species distribution models (SDMs) have become key tools for describing and predicting species habitats. In the marine domain, environmental data used in modeling species distributions are often remotely sensed, and as such have limited capacity for interpreting the vertical structure of the water column, or are sampled in situ, offering minimal spatial and temporal coverage. Advances in ocean models have improved our capacity to explore subsurface ocean features, yet there has been limited integration of such features in SDMs.
Read more below:
S. Brodie, M.G. Jacox, S.J. Bograd, H. Welch, H. Dewar, K.L. Scales, S.M. Maxwell, D.K. Briscoe, C.A. Edwards, L.B. Crowder, R.L. Lewison, and E.L. Hazen. 2018. Integrating dynamic subsurface habitat metrics into species distribution models. Frontiers in Marine Science. DOI: 10.3389/fmars.2018.00219. PDF
New computer-generated daily maps will help fishermen locate the most productive fishing spots in near real time while warning them where they face the greatest risk of entangling sea turtles, marine mammals, and other protected species. Scientists developed the maps, the products of a system called EcoCast, to help reduce accidental catches of protected species in fishing nets.
Funded primarily by NASA with support from NOAA, California Sea Grant, and Stanford University, Ecocast was developed by NOAA Fisheries scientists and academic partners with input from fishermen and managers.
E.L. Hazen, K.L. Scales, S.M. Maxwell, D. Briscoe, H. Welch, S.J. Bograd, H. Bailey, S.R. Benson, T. Eguchi, H. Dewar, S. Kohin, D.P. Costa, L.B. Crowder, R.L. Lewison. 2018. A dynamic ocean management tool to reduce bycatch and support sustainable fisheries. Science Advances, 4: eaar3001. PDF