Chris J. Harvey

The Role of Eelgrass in Marine Community Interactions and Ecosystem Services: Results from Ecosystem-Scale Food Web Models

Eelgrass beds provide valuable refuge, foraging, and spawning habitat for many marine species, including valued species such as Pacific salmon (Oncorhynchus spp.), Pacific herring (Clupea pallasi), and Dungeness crab (Metacarcinus magister). We used dynamic simulations in a food web model of central Puget Sound, Washington, USA developed in the Ecopath with Ecosim software, to examine how the marine community may respond to changes in coverage of native eelgrass (Zostera marina), and how these modeled responses can be assessed using an ecosystem services framework, expressing these services with economic currencies in some cases and biological proxies in others. Increased eelgrass coverage was most associated with increases in commercial and recreational fishing with some small decreases in one non-market activity, bird watching. When we considered ecosystem service categories that are aggregations of individual groups of species, we saw little evidence of strong tradeoffs among marine resources; that is, increasing eelgrass coverage was essentially either positive or neutral for all services we examined, although we did not examine terrestrial activities (for example, land use) that affect eelgrass coverage. Within particular service categories, however, we found cases where the responses to changes in eelgrass of individual groups of species that provide the same type of ecosystem service differed both in the magnitude and in the direction of change. This emphasizes the care that should be taken in combining multiple examples of a particular type of ecosystem service into an aggregate measure of that service.

Implementing “the IEA”: using integrated ecosystem assessment frameworks, programs, and applications in support of operationalizing ecosystem-based management

&NA; The Integrated Ecosystem Assessment (IEA) approach was designed to assimilate scientific knowledge in the ideal format for providing advice to inform marine Ecosystem‐Based Management (EBM). As such, IEAs were envisioned as the cornerstone integrated science product for the US National Oceanic and Atmospheric Administration (NOAA) that would maximize efficiencies and synergies across the agencys ecosystem science efforts. This led to the development of a NOAA IEA Program that would oversee regional implementation of the national IEA framework. As implementation proceeded, uptake by management entities was slower than anticipated, in part because EBM was not quickly embraced and applied to achieve management objectives. This slow movement to EBM in conjunction with the need to develop scientific analyses and methods to properly implement IEA resulted in the IEA process being viewed as its own endpoint. This commonly led to referring to “the IEA” when variously discussing the IEA framework, program, products, and process. Now that IEA and EBM are maturing, we need to be specific with what we are referring to when discussing IEAs, in order to develop reasonable expectations for applying IEA tools. We also now recognize the need to implement multiple IEA processes at varying geographic and complexity scales within an ecosystem to effectively meet the scientific requirements for operational EBM rather than viewing an IEA application as a single regional science product.

Stable Isotope Applications for Understanding Shark Ecology in the Northeast Pacific Ocean

Stable isotopes are used to address a wide range of ecological questions and can help researchers and managers better understand the movement and trophic ecology of sharks. Here, we review how shark studies from the Northeast Pacific Ocean (NEP) have employed stable isotopes to estimate trophic level and diet composition and infer movement and habitat-use patterns. To date, the number of NEP shark studies that have used stable isotopes is limited, suggesting that the approach is underutilized. To aid shark researchers in understanding the strengths and limitations of the approach, we provide a brief overview of carbon and nitrogen stable isotope trophic discrimination properties (e.g., change in δ15N between predator and prey), tissue sample preparation methods specific to elasmobranchs, and methodological considerations for the estimation of trophic level and diet composition. We suggest that stable isotopes are a potentially powerful tool for addressing basic questions about shark ecology and are perhaps most valuable when combined and analysed with other data types (e.g., stomach contents, tagging data, or other intrinsic biogeochemical markers).

Cooperative research sheds light on population structure and listing status of threatened and endangered rockfish species

Population genetics has increasingly become an important tool for determining appropriate taxonomic units for managing species of conservation interest. Yelloweye rockfish (Sebastes ruberrimus), canary rockfish (S. pinniger) and bocaccio (S. paucispinis) in the inland waterways of Puget Sound (PS), WA, USA were listed under the U.S. Endangered Species Act (ESA) in 2010. These listings relied heavily on evidence from other species that these populations were ‘discrete’ taxonomic units because little information was available for these species in PS. To fill this data gap, we collaborated with recreational fishing communities in PS to collect tissue samples and used population genetics analyses to determine whether samples from PS were genetically differentiated from samples collected from the outer coasts of the U.S. and Canada. Multiple analyses using restriction-site associated DNA sequencing data showed that yelloweye rockfish in PS and British Columbia, Canada were genetically different from coastal populations, while canary rockfish showed no genetic differentiation. These results support hypotheses that the genetic connectivity of rockfish populations is based on interactions between life-history characteristics and oceanographic conditions. These data also support the ESA designation status and the expansion of protected geographical boundaries for yelloweye rockfish but also suggest canary rockfish in PS are not a ‘discrete’ population and may not meet the first criterion of the ESA, as initially assumed. Collaboration among agencies and fishing communities, and cost-efficient genetic analyses provided a framework for collecting and analyzing data essential to the conservation and management of threatened and endangered species.