CS6.2 15:15 Cumulative sound exposure during offshore wind farm installation: implications for hearing damage in harbour seals. Hastie, G.D. *, Sea Mammal Research Unit; Russell, D.J.F. Sea Mammal Research Unit; McConnell, B. Sea Mammal Research Unit; Thompson, D. Sea Mammal Research Unit; Janik, V.M. Sea Mammal Research Unit; |
Abstract: Offshore pile driving is now widespread and with ambitious renewable energy targets in many countries, its use during offshore wind farm construction is likely to increase. Many proposed wind farms overlap with the at-sea distribution of seals and impact piling appears to have the potential to elicit overt behavioural responses or cause auditory damage. Here, we report on a study of harbour seal behaviour during the construction of a wind farm in the North Sea. We deployed GPS/GSM tags on 24 harbour seals during 2012. Tags provided location and activity data, allowing investigation of movements during pile driving, and a prediction of the potential for auditory damage in each seal. The closest range of individual seals to piling locations varied from 6.65 to 46.1 km. Received sound pressure levels (RLs) at each seal were estimated using data on the timing of every piling blow and Range Dependent Acoustic Models. To assess the potential for auditory injury, cumulative sound exposure levels (cSELs) were calculated for every seal. Although the prediction of auditory damage in marine mammals is a rapidly evolving field of research, based on published auditory injury criteria, our predictions suggest that most tagged seals received levels sufficient to cause at least temporary auditory threshold shifts. These results greatly enhance our understanding of the effects of impact pile driving on marine mammals.
CS6.3 15:20 BOEM Workshop Report: Quieting Technologies for Reducing Noise during Seismic Surveying and Pile Driving. CSA Ocean Sciences Inc. , CSA Ocean Sciences Inc.; Megan Butterworth *Bureau of Ocean Energy Management; |
Abstract: The Bureau of Ocean Energy Management (BOEM) manages the development of offshore energy and mineral resources. Protecting the environment while ensuring safe development is central to BOEMâ€™s mission. Noise resulting from offshore exploration and development activities is one impact BOEM must address in its environmental analyses. Recognizing that reducing noise is a valuable mitigation measure, BOEM convened the February 2013 â€śQuieting Technologies for Reducing Noise during Seismic Surveying and Pile Driving Workshop.â€ť At the workshop, representatives from regulatory agencies, energy industries, technology developers, non-governmental organizations (NGOs), and academia collaborated to gain a better understanding of current and emerging technologies to reduce noise produced by airguns, pile driving, and associated vessels. Information gaps were also identified to further study or evaluate the approach to noise quieting. The workshop outcomes can be utilized by various agencies, industries, NGOs, and academia to facilitate the advancement of noise quieting in the marine environment. A detailed workshop report is available for reference at boem.gov through the Environmental Studies Program Information System.
CS6.4 15:25 Importance of Cystoseira algal associations for mollusc fauna in the Gulf of Trieste (Northern Adriatic Sea). Pitacco, V *, Marine Biology Station (National Institute of Biology),Piran, Slovenia; Orlando-Bonaca, M Marine Biology Station (National Institute of Biology),Piran, Slovenia; MavriÄŤ, B Marine Biology Station (National Institute of Biology),Piran, Slovenia; PopoviÄ‡, A University of Primorska (FAMNIT), Koper, Slovenia; Lipej, L Marine Biology Station (National Institute of Biology), Piran, Slovenia; |
Abstract: Cystoseira species exert a role as habitat formers, providing habitat and shelter for smaller algae and invertebrates. In the Gulf of Trieste Cystoseira associations are distributed in a restricted shallow area and affected by many anthropogenic pressures. The present work evaluated the importance of these associations for marine biodiversity in terms of mollusc diversity. The sampling was performed during summers of 2008 and 2012 by SCUBA diving in the upper infralittoral belt (1 to 4 m depth) in the southern part of the Gulf of Trieste. The surface within frame samplers (20 x 20 cm) was scraped off and the fauna was collected by hands or with an air-lift sampler. Four erect algal species were dominant in the study area: Cystoseira barbata, C. compressa, C. corniculata and Halopithys incurva. Within those Cystoseira associations, a total of 69 species of molluscs were identified. Gastropoda were dominant for species richness and abundance. A large proportion of juveniles were found, proving the importance of studied associations for mollusc recruitment. Differences in composition and structure of mollusc assemblages were related with different morphology and degree of development of canopy-forming species. The present study confirms that dominant algal species within Cystoseira associations influence, at different levels, mollusc assemblages. Therefore, such habitat types deserve more research efforts and conservation actions for the maintenance of their good ecological status.
CS6.5 15:30 Role of seal colonies in the provision of carrion as a resource for scavenging seabirds. Quaggiotto, MM *, Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Graham Kerr Building, Glasgow, G12 8QQ, UK; Morris, C Sea Mammal Research Unit, Scottish Oceans Institute, East Sands, University of St Andrews, St Andrews, Fife, KY16 8LB, UK; Pickett, D Scottish Natural Heritage, 46 Crossgate, Cupar, Fife, KY15 5HS, UK; McCafferty, DJ Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Graham Kerr Building, Glasgow, G12 8QQ, UK; Bailey, DM Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Graham Kerr Building, Glasgow, G12 8QQ, UK; |
Abstract: Over the past 20 years nine of the commonest seabird species have declined in Scotland. Among them, the opportunistic great black-backed gull (Larus marinus) and the herring gull (Larus argentatus), decreased in abundance by more than 50% between 1986 and 2011. The great black backed gull is an important scavenger which remains largely coastal and commonly occurs at seal breeding sites. Seal colonies are essential providers of carrion derived from pup mortality to coastal environments. This project quantified the biomass and energy derived from grey seals carrion (Halichoerus grypus) from the Isle of May (56Â°11â€˛9â€łN 2Â°33â€˛27â€łW), Scotland, UK. Dead pups and placental biomass were similar between years. However, placenta was a high energy input despite its lower biomass. Total energy released to the system was estimated to be 13.88 MJ (Â± SE 0.4). The importance of carrion for scavengers is not well known and understanding its ecological role provides a basis for the conservation and protection of important breeding colonies. This is especially important when previous sources of carrion from fish discards are reduced.
CS6.6 15:35 Marine Tourism as a Platform of Research: Studying the Social Structure of Feeding Humpback Whales (Megaptera novaeangliae) in the Gulf of Maine. Weilermann. D *, Scottish Association for Marine Science, Oban, Argyll PA37 1QAT, Scotland, UK; Wilson, B Scottish Association for Marine Science, Oban, Argyll PA37 1QAT, Scotland, UK; Benjamins, S Scottish Association for Marine Science, Oban, Argyll PA37 1QAT, Scotland, UK; Schulte, D Blue Ocean Society for Marine Conservation, Portsmouth, New Hampshire, USA; Robbins, J Provincetown Center for Coastal Studies, Provincetown, Massachusetts, USA; |
Abstract: Humpback whales have the potential for a complex social structure as they show strong site fidelity between feeding and breeding grounds. We aimed to study the social structure and to determine if long-term associations exist in humpback whales feeding at Jeffreys Ledge in the Gulf of Maine (USA). Between 2002 and 2012 opportunistic humpback whale sightings were recorded from 4 whale watching boats in New Hampshire and Massachusetts, and associations between individuals were documented. Whales were considered associated when they were within two body lengths of each other and showed coordinated surface and diving behaviours. A total of 2133 sightings were used. The mean group size was 1.34 (SDÂ±0.63). 68% of sightings were single animals, followed by pairs (26%) and trios (5%). For the social structure individuals were divided into 4 age-sex classes: juveniles, lactating females, non-lactating females and mature males and data (n = 238) were analysed with SOGPROG 2.4. Significant differences in associations between and within age-sex classes were found. Males did not avoid each other and juveniles were more social than previously thought. Long-term associations among non-lactating females were observed; however the strongest bond was found between a male and non-lactating female. Though results are consistent with humpback whales being more solitary than social animals, when grouping they show preferred companionship, suggesting individual recognition and selectivity.