The conservation of marine birds cannot be accomplished without national laws, international and regional treaties, and multilateral agreements that protect components of the environment, such as lands that provide breeding habitats for seabirds and marine areas that provide foraging habitat, or that control human behavior to address pollution, exploitation, or fishing in a manner to prevent or reduce harm to seabirds. We provide an overview of these legal and cooperative mechanisms that underpin much conservation activity. We then describe protections on land, including a survey of parks, refuges, and sanctuaries on all continents, as well as the means by which countries protect species directly. The at-sea protections described include several marine protected areas that have seabirds considered in their design and the management of fisheries by regional fisheries management organizations, particularly conservation and management measures for mitigating seabird bycatch. Laws and treaties preventing oil and plastic pollution in the marine environment are also reviewed as they serve to prevent harm to seabirds. The conglomeration of these legal and cooperative mechanisms reflects the value and care of communities across the globe in protecting seabirds and their environment. While much progress has been made on conserving seabirds, additional efforts, such as improving the effectiveness of, and compliance with, existing laws and conservation measures, are essential for the recovery of seabird populations and preventing the loss of seabird species.

This paper describes the tensions between the legal requirements for conservation and the most beneficial biological practice for mobile transnational marine species, using the harbour porpoise (Phocoena phocoena) in European Atlantic waters as a case study. Harbour porpoise are the smallest and one of the most abundant cetaceans occurring throughout the European continental shelf waters, and are affected by human activities occurring in the same waters, especially certain fishing activities. The Convention on the Conservation of European Wildlife and Natural Habitats (the Bern Convention) and its implementing legislation the Council Directive on the Conservation of Natural Habitats and of Wild Fauna and Flora 92/43/EEC (i.e. the Habitats Directive) are the main legal drivers for species conservation throughout the European Union. They aim for the long-term achievement of favourable conservation status and make provision for the use of two conservation measures: protected areas and strict protection measures. The strict protection measures aim to ensure that all forms of deliberate killing are prevented, and that where incidental killing and capture occurs, it does not have a negative effect on conservation status. The conservation of harbour porpoise is currently dependent upon tackling the key issue of bycatch in fisheries. However, in challenges to Member States on their application of the Habitats Directive, the European Commission has chosen to focus on site designation rather than the implementation of the strict protection measures required to monitor and, where necessary, reduce bycatch. This tension between a legal focus on the designation of protected areas instead of tackling threats such as bycatch has potentially led to negative conservation consequences for harbour porpoise and, in part, may explain why wider marine biodiversity has continued to deteriorate in Europe.

The European Union Marine Strategy Framework Directive (MSFD) aims to achieve good environmental status (GES) in European seas by 2020. One of the features of GES is that underwater sound should not adversely affect the marine environment. Direct injury of marine life may occur, but a more pervasive effect is likely to be through the cumulative indirect effects on behavior. Assessing the significance of these effects on an ecosystem scale is difficult. If subsequent management of these effects is required, complex and challenging international decisions will be required.

The European Marine Strategy Framework Directive requires European member states to develop strategies for their marine waters leading to programs of measures that achieve or maintain good environmental status (GES) in all European seas by 2020. An essential step toward reaching GES is the establishment of monitoring programs, enabling the state of marine waters to be assessed on a regular basis. A register for impulsive noise-generating activities would enable assessment of their cumulative impacts on wide temporal and spatial scales; monitoring of ambient noise would provide essential insight into current levels and any trend in European waters.

The Marine Directors of the European Union (EU), Acceding Countries, Candidate Countries and EFTA Countries have jointly developed a common strategy for supporting the implementation of the Directive 2008/56/EC, “the Marine Strategy Framework Directive” (MSFD). The main aim of this strategy is to allow a coherent and harmonious implementation of the Directive. Focus is on methodological questions related to a common understanding of the technical and scientific implications of the Marine Strategy Framework Directive. In particular, one of the objectives of the strategy is the development of non-legally binding and practical documents, such as this technical guidance on monitoring for the MSFD. These documents are targeted to those experts who are directly or indirectly implementing the MSFD in the marine regions. The document has been prepared by the Joint Research Centre of the European Commission (JRC) with the contribution of experts from Member States, Regional Seas Conventions and ICES and following consultation of the Working Group on Good Environmental Status. L B -N A -2 6 4 9 9 -E N -N L B -N A -2 6 4 9 9 -E N -N

estimates and improving survey efficiency – a response to MacLeod Philip S Hammond, Kelly Macleod, Per Berggren, David L Borchers, Louise Burt, Ana Canadas, Genevieve Desportes, Greg P Donovan, Anita Gilles, Douglas Gillespie, Jonathan Gordon, Russell Leaper, Kristina Lehnert, Mardik Leopold, Phil Lovell, Nils Oien, Charles GM Paxton, Vincent Ridoux, Emer Rogan, Filipa Samarra, Meike Scheidat, Ursula Siebert, Henrik Skov, Rene Swift, Mark L Tasker, Jonas Teilmann, Olivier Van Canneyt, Jose Antonio Vazquez a Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, Fife KY16 8LB, UK. b Joint Nature Conservation Committee, Inverdee House, Baxter Street, Aberdeen AB11 9QA, UK. c School of Marine Science and Technology, Dove Marine Laboratory, Newcastle University, Cullercoats, North Shields, Tyne and Wear, NE30 4PZ, UK. d Centre for Research into Ecological and Environmental Modelling, Buchanan Gardens, University of St Andrews, St Andrews, Fife KY16 9LZ, UK. e Alnilam Investigacion y Conservacion, Candamo 116, 28240 Hoyo de Manzanares, Madrid, Spain. f GDnatur, DK-5300 Kerteminde, Denmark. g International Whaling Commission, The Red House, 135 Station Road, Impington, Cambridge CB4 9NP, UK. h Institute for Terrestrial and Aquatic Wildlife Research (ITAW), University of Veterinary Medicine Hannover Foundation (TiHo), Werftstr. 6, 25761 Busum, Germany. i Ecologic, 7 Beechwood Terrace West, Newport on Tay, Fife DD6 8JH, UK. j International Fund for Animal Welfare, 87-90 Albert Embankment, London SE1 7UD, UK. k IMARES Institute for Marine Resources and Ecosystem Studies, PO Box 167, 1790 AD Den Burg, The Netherlands. l Institute of Marine Research, PO Box 1870 Nordnes, N-5817 Bergen, Norway. m Littoral, Environnement et Societes, UMR 6250, Universite de La Rochelle / CNRS, 2 rue Olympe de Gouges, 17032 La Rochelle, Cedex France. n School of Biological, Earth and Environmental Sciences, University College Cork, Distillery Fields, North Mall, Cork, Ireland. o DHI, Agern Alle 5, DK-2920 Horsholm, Denmark. p Department of Bioscience, Aarhus University, Frederiksborgvej 399, DK-4000, Roskilde, Denmark. q Centre de Recherche sur les Mammiferes Marins, Observatoire Pelagis, UMS 3462, Universite de La Rochelle, CNRS, Pole Analytique, 5 allees de l’Ocean, 17000 La Rochelle, France. r Sociedad Espanola de Cetaceos, Cabeza de Manzaneda 3, Algeciras, Pelayo, 11390, Spain.

On 9 June 2008, the UK's largest mass stranding event (MSE) of short-beaked common dolphins (Delphinus delphis) occurred in Falmouth Bay, Cornwall. At least 26 dolphins died, and a similar number was refloated/herded back to sea. On necropsy, all dolphins were in good nutritive status with empty stomachs and no evidence of known infectious disease or acute physical injury. Auditory tissues were grossly normal (26/26) but had microscopic haemorrhages (5/5) and mild otitis media (1/5) in the freshest cases. Five lactating adult dolphins, one immature male, and one immature female tested were free of harmful algal toxins and had low chemical pollutant levels. Pathological evidence of mud/seawater inhalation (11/26), local tide cycle, and the relative lack of renal myoglobinuria (26/26) suggested MSE onset on a rising tide between 06:30 and 08∶21 hrs (9 June). Potential causes excluded or considered highly unlikely included infectious disease, gas/fat embolism, boat strike, by-catch, predator attack, foraging unusually close to shore, chemical or algal toxin exposure, abnormal weather/climatic conditions, and high-intensity acoustic inputs from seismic airgun arrays or natural sources (e.g., earthquakes). International naval exercises did occur in close proximity to the MSE with the most intense part of the exercises (including mid-frequency sonars) occurring four days before the MSE and resuming with helicopter exercises on the morning of the MSE. The MSE may therefore have been a "two-stage process" where a group of normally pelagic dolphins entered Falmouth Bay and, after 3-4 days in/around the Bay, a second acoustic/disturbance event occurred causing them to strand en masse. This spatial and temporal association with the MSE, previous associations between naval activities and cetacean MSEs, and an absence of other identifiable factors known to cause cetacean MSEs, indicates naval activity to be the most probable cause of the Falmouth Bay MSE.

The European Union (EU) Habitats Directive requires Member States to monitor and maintain at favourable conservation status those species identified to be in need of protection, including all cetaceans. In July 2005 we surveyed the entire EU Atlantic continental shelf to generate robust estimates of abundance for harbour porpoise and other cetacean species. The survey used line transect sampling methods and purpose built data collection equipment designed to minimise bias in estimates of abundance. Shipboard transects covered 19,725 km in sea conditions <= Beaufort 4 in an area of 1,005,743 km(2). Aerial transects covered 15,802 km in good/moderate conditions (<= Beaufort 3) in an area of 364,371 km(2). Thirteen cetacean species were recorded; abundance was estimated for harbour porpoise (375,358; CV = 0.197), bottlenose dolphin (16,485; CV = 0.422), white-beaked dolphin (16,536; CV = 0.303), short-beaked common dolphin (56,221; CV = 0.234) and minke whale (18,958; CV = 0.347). Abundance in 2005 was similar to that estimated in July 1994 for harbour porpoise, white-beaked dolphin and minke whale in a comparable area. However, model-based density surfaces showed a marked difference in harbour porpoise distribution between 1994 and 2005. Our results allow EU Member States to discharge their responsibilities under the Habitats Directive and inform other international organisations concerning the assessment of conservation status of cetaceans and the impact of bycatch at a large spatial scale. The lack of evidence for a change in harbour porpoise abundance in EU waters as a whole does not exclude the possibility of an impact of bycatch in some areas. Monitoring bycatch and estimation of abundance continue to be essential. (C) 2013 The Authors. Published by Elsevier Ltd. All rights reserved.