Estimating recreational harvest of surf smelt Hypomesus pretiosus via a combined access point and roving creel count design

Fisheries for surf smelt Hypomesus pretiosus in Washington State are currently managed under the assumption that recreational harvest is roughly comparable to commercial harvest on a Puget Sound-wide basis. This assumption may underestimate total fishing pressure and harvest, leading to localized or Sound-wide depletion and negative ecosystem impacts. Assessing recreational effort and harvest is complicated by the lack of a licensing requirement for fishers, the fact that fishing occurs throughout the year but tends to peak during locally specific time windows, and the ability of anglers to engage in the fishery from private shorelines in addition to public access points (e.g., boat ramps). In order to adequately estimate total recreational harvest a survey method must be developed that accounts for spatiotemporally diverse harvest patterns over the entirety of Puget Sound. This presentation will report the results of a pilot study that combines access point and roving, boat-based creel survey techniques to sample a known region of high recreational fishing pressure along the northern shore of Camano island, Puget Sound, WA during the traditional fishing ‘season.’ In addition to providing an estimate of harvest during this period in this location (4419 lbs), patterns of both fishing effort and catch are described through time, in association with tidal and other environmental variables, and compared between public access points and private beaches. We find that, based on the site-specific estimate generated here, the capacity for Sound-wide recreational harvest to exceed the assumed 100,000 lbs exists and that additional monitoring is warranted. We conclude that by further optimizing sample size in both time and space a logistically feasible design can be developed that will allow estimation of recreational smelt harvest for the entirety of Puget Sound

Dynamic metapopulation structure of Pacific herring in Puget Sound

Metapopulation structure in herring has been postulated for decades, yet the dynamics of extinction and recolonization and their effect of population genetic structure have not been directly observed. As a consequence, herring populations are often seen as spatially static (albeit demographically dynamic) entities for conservation and management purposes. Here, we present microsatellite data for Pacific herring population structure over 15 years (1999-2014) throughout the Southern Salish Sea. Genetic structure was primarily determined by spawn timing, but also by geographic isolation in the southern basin. Some populations experienced well described population declines, but there were also recent colonization events. Genetic analysis of a recently established spring spawning stock at the Seattle waterfront suggested Puget Sound winter spawners as the primary source of colonizers, similar to a recently discovered winter spawning stock in the southern basin. These results suggest that spawn timing and location may determine extant genetic structure, but that colonization events may originate from populations in a different location or spawning at a different time. These patterns correspond very well to the adopted migrant hypothesis, inferring learning behavior in herring natal homing. More broadly, our results suggest that the goal herring management should include not only the conservation of individual spawning populations and standing genetic and phenotypic diversity, but also the preservation and restoration of both utilized and unutilized spawning habitats to facilitate natural processes of extirpation colonization within a dynamic metapopulation. For this approach to work, it is important to understand key attributes of nearshore habitats that support herring spawning and to enact comprehensive protection measures that ensure persistence of appropriate locations on a biologically relevant geographic scale

Herring reproductive success in Puget Sound: spawning habitat availability and quality, spatial variation in egg survival, and the specter of habitat limitation

It is well known that Pacific herring migrate into areas of Puget Sound each winter and spring and spawn on submerged vegetation in shallow nearshore waters. However, we do not understand how the availability and quality of nearshore spawning habitat affects herring egg survival or herring populations. To understand the interplay between nearshore habitat and herring egg success, we measured the survival of wild spawned herring eggs from 5 Puget Sound populations under field and laboratory conditions. We estimated enormous variation in herring egg loss among sites under both field conditions (range of daily loss rates: 5 to 70%) and laboratory conditions (mortality ranged from 20 to 100% over the ~ 7 day incubation). Taking egg loss and mortality rates together with predictions based on field incubation temperatures, we estimated herring hatch probabilities ranging from 0.25 to 10-9. Egg loss and mortality rates varied by site, but not by spawning substrate type. Exploratory analyses revealed the potential influence of wave action and shoreline urbanization on probabilities of hatch success. Using historical records of herring spawn, we determined that herring eggs are not found on any substrate type in greater proportions than expected by chance, with the exception that they are more likely to be found on the non-indigenous brown alga, Sargassum muticum. Last, we found that a large proportion of suitable spawning habitat available to Puget Sound herring at these sites remains unused. Our results demonstrate that Puget Sound herring at these sites are not limited by the amount of suitable spawning substrate, and that native vegetation is not preferred over other vegetation types for herring spawning. Rather, it appears that other land-based or oceanographic variables are more important for determining herring hatch success in Puget Sound