Pacific Halibut Bycatch in IPHC Area 2A in 2002

This report updates the estimate of Pacific halibut bycatch and mortality in the bottom trawl fishery through the calendar year 2002. The estimate of halibut bycatch and mortality in the bottom trawl fishery is based upon the method developed in the report for 1999 (Wallace, 2000) This report uses halibut bycatch rates observed from 31 August 2001 thru 28 August 2002 in the West Coast Groundfish Observer Program. These rates are stratified by season, depth, latitude, and level of arrowtooth flounder catch, then multiplied by the amount of trawl effort in each stratum determined from Oregon and Washington trawl logbooks in 2002. Estimated halibut bycatch and mortality in other gear types has not been updated for 2002. The estimate for the 2002 bottom trawl fishery is 512,000 lbs net weight of total halibut bycatch mortality of which 286,000 lbs is legal-sized. The net weight is 64 % lower than in 2001. As in past reports, forecast of bycatch for the current year (2003) or future years is not attempted. 1 GROUNDFISH FISHERY BACKGROUND Changes in the groundfish fishery and its management affect the amount of groundfish fishing effort and the geographic and temporal distribution of this effort. These changes will affect th

Harbour porpoise distribution can vary at small spatiotemporal scales in energetic habitats

The authors acknowledge support received from the Scottish Funding Council, Highlands & Islands Enterprise, Scottish Power Renewables and E.ON under the Hebridean Marine Energy Futures (HMEF) programme (Grant reference number 1R042 (HFU) SPIRIT , Project Ref. HR10012), a research initiative led by the University of the Highlands and Islands (UHI) and Aquamarine Power. Scarba C-POD data were collected under the UK Natural Environment Research Council (DEFRA/NERC) grant NE/J004367/1 (RESPONSE).Marine habitat heterogeneity underpins species distribution and can be generated through interactions between physical and biological drivers at multiple spatiotemporal scales. Passive acoustic monitoring (PAM) is used worldwide to study potential impacts of marine industrial activities on cetaceans, but understanding of animals’ site use at small spatiotemporal scales (<1 km, <1 day) remains limited. Small-scale variability in vocalising harbour porpoise (Phocoena phocoena) distribution within two Scottish marine renewable energy development (MRED) sites was investigated by deploying dense arrays of C-POD passive acoustic detectors at a wave energy test site (the European Marine Energy Centre [Billia Croo, Orkney]) and by a minor tidal-stream site (Scarba [Inner Hebrides]). Respective arrays consisted of 7 & 11 moorings containing two C-PODs each and were deployed for up to 55 days. Minimum inter-mooring distances varied between ~300–600 m. All C-POD data were analysed at a temporal resolution of whole minutes, with each minute classified as 1 or 0 on the basis of presence/absence of porpoise click trains (Porpoise-Positive Minutes/PPMs). Porpoise detection rates were analysed using Generalised Additive Models (GAMs) with Generalised Estimation Equations (GEEs). Although there were many porpoise detections (wave test site: N = 3,432; tidal-stream site: N = 17,366), daily detection rates varied significantly within both arrays. Within the wave site array (<1 km diameter), average daily detection rates varied from 4.3–14.8 PPMs/day. Within the tidal-stream array (<2 km diameter), average daily detection rates varied from 10.3–49.7 PPMs/day. GAM-GEE model results for individual moorings within both arrays indicated linkages between porpoise presence and small-scale heterogeneity among different environmental covariates (e.g. tidal phase, time of day). Porpoise detection rates varied considerably but with coherent patterns between moorings only several hundred metres apart and within hours. These patterns presumably have ecological relevance. These results indicate that, in energetically active and heterogeneous areas, porpoises can display significant spatiotemporal variability in site use at scales of hundreds of metres and hours. Such variability will not be identified when using solitary moored PAM detectors (a common practice for site-based cetacean monitoring), but may be highly relevant for site-based impact assessments of MRED and other coastal developments. PAM arrays encompassing several detectors spread across a site therefore appear to be a more appropriate tool to study site-specific cetacean use of spatiotemporally heterogeneous habitat and assess the potential impacts of coastal and nearshore developments at small scales.Publisher PDFPeer reviewe

Harbour seals avoid tidal turbine noise: implications for collision risk

1. Tidal stream energy converters (turbines) are currently being installed in tidally energetic coastal sites. However, there is currently a high level of uncertainty surrounding the potential environmental impacts on marine mammals. This is a key consenting risk to commercial introduction of tidal energy technology. Concerns derive primarily from the potential for injury to marine mammals through collisions with moving components of turbines. To understand the nature of this risk, information on how animals respond to tidal turbines is urgently required. 2. We measured the behaviour of harbour seals in response to acoustic playbacks of simulated tidal turbine sound within a narrow coastal channel subject to strong, tidally induced currents. This was carried out using data from animal-borne GPS tags and shore-based observations, which were analysed to quantify behavioural responses to the turbine sound. 3. Results showed that the playback state (silent control or turbine signal) was not a significant predictor of the overall number of seals sighted within the channel. 4. However, there was a localised impact of the turbine signal; tagged harbour seals exhibited significant spatial avoidance of the sound which resulted in a reduction in the usage by seals of between 11 and 41% at the playback location. The significant decline in usage extended to 500 m from the playback location at which usage decreased by between 1 and 9% during playback. Synthesis and applications: This study provides important information for policy makers looking to assess the potential impacts of tidal turbines and advise on development of the tidal energy industry. Results showing that seals avoid tidal turbine sound suggest that a proportion of seals encountering tidal turbines will exhibit behavioural responses resulting in avoidance of physical injury; in practice, the empirical changes in usage can be used directly as avoidance rates when using collision risk models to predict the effects of tidal turbines on seals. There is now a clear need to measure how marine mammals behave in response to actual operating tidal turbines in the long term to learn whether marine mammals and tidal turbines can co-exist safely at the scales currently envisaged for the industry

Childhood Incident Asthma and Traffic-Related Air Pollution at Home and School

Background: Traffic-related air pollution has been associated with adverse cardiorespiratory effects, including increased asthma prevalence. However, there has been little study of effects of traffic exposure at school on new-onset asthma. Objectives: We evaluated the relationship of new-onset asthma with traffic-related pollution near homes and schools. Methods: Parent-reported physician diagnosis of new-onset asthma (n = 120) was identified during 3 years of follow-up of a cohort of 2,497 kindergarten and first-grade children who were asthma- and wheezing-free at study entry into the Southern California Children's Health Study. We assessed traffic-related pollution exposure based on a line source dispersion model of traffic volume, distance from home and school, and local meteorology. Regional ambient ozone, nitrogen dioxide (NO2), and particulate matter were measured continuously at one central site monitor in each of 13 study communities. Hazard ratios (HRs) for new-onset asthma were scaled to the range of ambient central site pollutants and to the residential interquartile range for each traffic exposure metric. Results: Asthma risk increased with modeled traffic-related pollution exposure from roadways near homes [HR 1.51; 95% confidence interval (CI), 1.25-1.82] and near schools (HR 1.45; 95% CI, 1.06-1.98). Ambient NO2 measured at a central site in each community was also associated with increased risk (HR 2.18; 95% CI, 1.18-4.01). In models with both NO2 and modeled traffic exposures, there were independent associations of asthma with traffic-related pollution at school and home, whereas the estimate for NO2 was attenuated (HR 1.37; 95% CI, 0.69-2.71). Conclusions: Traffic-related pollution exposure at school and homes may both contribute to the development of asthma. Editor's SummaryTraffic-related air pollution has been associated with adverse cardiorespiratory effects, including increased asthma prevalence. McConnell et al. (p. 1021) evaluated the relationship of new-onset asthma with traffic-related pollution near homes and schools. Parent-reported physician diagnosis of new-onset asthma was identified during 3 years of follow-up of a cohort of kindergarten and first-grade children who were asthma- and wheezing-free at study entry into the Southern California Children's Health Study. Traffic-related pollution exposure was assessed based on a line source dispersion model of traffic volume, distance from home and school, and local meteorology. Regional ambient ozone, nitrogen dioxide (NO2), and particulate matter were measured continuously at one central site monitor in each of 13 study communities. The authors report an increase in asthma risk with modeled traffic-related pollution exposure from roadways near homes and schools. Ambient NO2 was also associated with increased risk. Models that included both NO2 and modeled traffic exposures suggested independent associations of asthma with traffic-related pollution at school and at home, whereas the estimate for NO2 was attenuated. The authors conclude that traffic-related pollution exposure at school and home may both contribute to the development of asthma

Distribution and abundance of cephalopods in UK waters: long-term trends and environmental relationships

As part of a project which aimed to evaluate the feasibility of developing indicators of marine ecosystem status based on cephalopods, we analysed spatiotemporal variation in abundance,, and environmental relationships, using trawl survey catch data for cephalopods in UK waters (1980-2013) from Cefas and Marine Scotland Science databases. These data presented some challenges, notably the use of several different trawl gears, variable tow durations, and varying levels of taxonomic resolution. Accounting for gear type and tow duration, data were analysed separately for each cephalopod family and season to account for different phases of the life cycles being present at different times of year. The families investigated were Loliginidae, Octopodidae, Ommastrephidade, Sepiidae and Sepiolidae. A GAM framework was used to summarise spatiotemporal variation in abundance at family level and the relationships of spatial and long-term temporal variation with environmental variables, including depth, substrate (available for inshore waters) and several oceanographic variables (e.g., SST, chl signals), also considering fishing pressure. Long-term trends for each family varied between areas and seasons, although this may reflect the presence of several species within families. In Scotland, where Loligo vulgaris is rare and L. forbesii is normally distinguished from Alloteuthis spp., survey data suggested a peak in abundance of this species around 1990 and a generally increasing trend since the mid-1990s. Spatial patterns in distribution in all families were related to both physiographic and oceanographic features. As expected substrate type had most effect on those families in which eggs are attached to objects on the seabed

Comparing spatial patterns of marine vessels between vessel-tracking data and satellite imagery

Monitoring marine use is essential to effective management but is extremely challenging, particularly where capacity and resources are limited. To overcome these limitations, satellite imagery has emerged as a promising tool for monitoring marine vessel activities that are difficult to observe through publicly available vessel-tracking data. However, the broader use of satellite imagery is hindered by the lack of a clear understanding of where and when it would bring novel information to existing vessel-tracking data. Here, we outline an analytical framework to (1) automatically detect marine vessels in optical satellite imagery using deep learning and (2) statistically contrast geospatial distributions of vessels with the vessel-tracking data. As a proof of concept, we applied our framework to the coastal regions of Peru, where vessels without the Automatic Information System (AIS) are prevalent. Quantifying differences in spatial information between disparate datasets—satellite imagery and vessel-tracking data—offers insight into the biases of each dataset and the potential for additional knowledge through data integration. Our study lays the foundation for understanding how satellite imagery can complement existing vessel-tracking data to improve marine oversight and due diligence

Pacific Halibut Bycatch in IPHC Area 2A

This report updates the estimates of Pacific halibut bycatch and mortality in the portion of the limited-entry groundfish bottom trawl fishery that operates between 48˚.667 and 40˚.667 degrees through the calendar year 2008. The estimates of halibut bycatch and mortality in the bottom trawl fishery are based upon the method developed in the report for 1999 (Wallace, 2000). The current report uses halibut bycatch rates observed during the 2008 calendar year by the West Coast Groundfish Observer Program (WCGOP). These rates are stratified by season, depth, latitude, and amount of arrowtooth flounder catch, and then multiplied by the amount of 2008 trawl effort (hours towed) in each stratum determined from Oregon and Washington trawl logbooks. Estimated halibut bycatch and mortality from other gear types targeting groundfish has not been updated for 2008 at this time. As was done for the first time last year, this analysis continues to use the WCGOP observations of the viability of discarded halibut for determining the mortality rates used in calculating the amounts of mortality. In 2008, the amount of bottom trawl effort increased by 23 % relative to 2007, and effort continued to shift to depths seaward of the RCA. The total amount of halibut bycatch (437,689 lb) represents a 35 % increase over 2007

e. Council Action: Provide Guidance on Bycatch Estimation Issues

on the status of bycatch estimates for Pacific halibut in the Council-area groundfish trawl fishery. The halibut bycatch estimates for the 2002 groundfish trawl fishery in International Pacific Halibut Commission (IPHC) Area 2A waters include information from the groundfish observer program and effects of the groundfish area closures in 2002. A report was provided to the Scientific and Statistical Committee (SSC) for review with the intent of providing estimates to the IPHC to use in establishing the 2004 halibut fisheries (Attachment 1). Council Action: 1. Utilizing input from the SSC, provide any needed Council guidance to the completion o

Data from: Harbour seals avoid tidal turbine noise: implications for collision risk

1. Tidal stream energy converters (turbines) are currently being installed in tidally energetic coastal sites. However, there is currently a high level of uncertainty surrounding the potential environmental impacts on marine mammals. This is a key consenting risk to commercial introduction of tidal energy technology. Concerns derive primarily from the potential for injury to marine mammals through collisions with moving components of turbines. To understand the nature of this risk, information on how animals respond to tidal turbines is urgently required. 2. We measured the behaviour of harbour seals in response to acoustic playbacks of simulated tidal turbine sound within a narrow coastal channel subject to strong, tidally induced currents. This was carried out using data from animal-borne GPS tags and shore-based observations, which were analysed to quantify behavioural responses to the turbine sound. 3. Results showed that the playback state (silent control or turbine signal) was not a significant predictor of the overall number of seals sighted within the channel. 4. However, there was a localised impact of the turbine signal; tagged harbour seals exhibited significant spatial avoidance of the sound which resulted in a reduction in the usage by seals of between 11 and 41% at the playback location. The significant decline in usage extended to 500 m from the playback location at which usage decreased by between 1 and 9% during playback. 5. Synthesis and applications: This study provides important information for policy makers looking to assess the potential impacts of tidal turbines and advise on development of the tidal energy industry. Results showing that seals avoid tidal turbine sound suggest that a proportion of seals encountering tidal turbines will exhibit behavioural responses resulting in avoidance of physical injury; in practice, the empirical changes in usage can be used directly as avoidance rates when using collision risk models to predict the effects of tidal turbines on seals. There is now a clear need to measure how marine mammals behave in response to actual operating tidal turbines in the long term to learn whether marine mammals and tidal turbines can co-exist safely at the scales currently envisaged for the industry