Biodiversity impacts of ship movement, noise, grounding and anchoring

Marine life in the Mediterranean Sea is threatened by intensive human activities such as fisheries, ship traffic, pollution and coastal development. Cetaceans and other vertebrates are affected not only by chemical pollution, but also by noise pollution (Richardson et al., 1995; Simmonds et al., 2004). Noise has become a ubiquitous form of marine pollution, especially in areas of heavy maritime traffic and along developed coasts. Intense underwater noise is generated by airguns, widely used for geophysical exploration in the oil and gas industry as well as for academic and government research purposes; by high power sonar, either military or civilian; by ship traffic; by shoreline and offshore construction works; and by a number of other commercial, scientific, military and industrial sources. The most powerful noises (from airguns, sonars, and explosions) may directly injure animals in the vicinity of the source. General ship traffic, heavy industries on the coast and a variety of other human activities generally do not generate such intense noise, but the acoustic pollution they produce is constant over time and may affect large areas. It may be a serious hazard not only to individual animals, but also to entire populations. Such increased background noise affects underwater life just as airborne noise affects terrestrial animals, including human beings.peer-reviewe

Movements, diving behaviour and diet of C-type killer whales (Orcinus orca) in the Ross Sea, Antarctica

The fish‐eating, type‐C ecotype, killer whale is a top predator in the Ross Sea, Antarctica. Increasing knowledge of this animal's foraging habitats, diet and movement patterns is listed amongst the research priorities adopted under the framework of the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR). To contribute to this goal, satellite transmitters were deployed on 10 type‐C killer whales and skin biopsies were obtained from seven individuals in Terra Nova Bay (Ross Sea) during austral summer (January-February) 2015. Hierarchical switching state-space models (hSSSM) were applied to Argos satellite tracking data to describe the movements of tagged whales, which were then paired with available diving data. Stable isotopes analyses were performed on the biopsy samples to describe the diet. A total of 8,803 Argos locations were available to fit the hSSSM. All whales engaged in potential foraging activity in localized areas along the Ross Sea coastline, followed by uninterrupted travel (i.e. migration) outside Antarctic waters, with no evidence of foraging activity. The pattern of deeper dives matched the occurrence of encamped behaviour indicated by the hSSSM results. The stable isotopes analysis indicated that Antarctic toothfish comprised the largest component (35%) of the prey biomass, raising concerns since this species is targeted by commercial fishery in the Ross Sea Region. These results provide new insights into the ecology of type‐C killer whales in the Ross Sea Region, underlining a potential threat from commercial fishing in the area. Considering the recent establishment of the Ross Sea Region Marine Protected Area, these findings will contribute to the required Research and Monitoring Programme of the Marine Protected Area and provide new empirical evidence to inform conservation measures in the existing Terra Nova Bay Antarctic Special Protected Are

Acoustic estimates of sperm whale abundance in the Mediterranean Sea as part of the ACCOBAMS Survey Initiative

Acoustic surveys for sperm whales (Physeter macrocephalus) were conducted in the Mediterranean Sea in summer 2018 as part of the vessel-based component of the ACCOBAMS Survey Initiative (ASI). Equal-spaced zigzag transects provided uniform coverage of key sperm whale habitats and were surveyed using a towed hydrophone array deployed from a research vessel at speeds of 5-8 knots. A total of 14,039 km of tracklines were surveyed in the western basin, Hellenic Trench and Libyan waters, with an acoustic coverage of 10% realised for sperm whales. During these surveys, 254 individual sperm whales were detected on the trackline, with an additional 66 individuals off-track. Sperm whales were only seen ten times on-track, with an additional 16 off-track sightings. Estimates of slant range to echolocating whales were used to derive density estimates through both design- and model-based distance sampling methodologies. An acoustic availability of 0.912 (sd = 0.036) was derived from via published models. When correcting for availability bias, a design-based abundance estimates of 2,673 individuals (95% CI 1,739-4,105; CV = 0.21) was derived for the surveyed blocks, which incorporated most known sperm whale habitat in the Mediterranean Sea. The equivalent model-based estimate was 2,825 whales (2,053-3,888; CV = 0.16). Over 97% of detected whales were in the western basin, with highest densities in the Algerian and Liguro-Provencal Basins between Algeria and Spain/France. In the eastern basin, detections were sparse and concentrated along the Hellenic Trench. A density surface modelling (DSM) exercise identified location and benthic aspect as being the most instructive covariates for predicting whale abundance. Distance sampling results were used in a power analysis to quantify the survey effort required to identify population trends. In the most extreme scenario modelled (10% per annum decline with decennial surveys), the population could have dropped by 90% before the decline was identified with high statistical power. Increasing the regularity of surveys would allow population trends to be detected more expediently. Mediterranean sperm whales are listed as Endangered on the IUCN’s Red List and the need for urgent conservation measures to reduce injury and mortality remains paramount for this unique sub-population

The Important Marine Mammal Area network : a tool for systematic spatial planning in response to the marine mammal habitat conservation crisis

Major support to the IMMA process was provided by the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU) on the basis of a decision adopted by the German Bundestag, through the Global Ocean Biodiversity Initiative (GOBI). Funding was also provided by the MAVA Foundation and by the French Biodiversity Agency (OFB) in cooperation with IUCN’s Global Marine and Polar Program. The support from the Prince Albert II of Monaco Foundation, OceanCare, NRDC, the Animal Welfare Institute, and the Pacific Life Foundation is also gratefully acknowledged.The Important Marine Mammal Areas (IMMAs) initiative was launched by the Marine Mammal Protected Areas Task Force of the International Union for the Conservation of Nature in 2016, as a response to a conservation crisis in the protection of marine mammals and wider global ocean biodiversity. IMMAs identify discrete portions of habitat that are important for one or more marine mammal species, and that have the potential to be delineated and managed for conservation. They are identified by scientific experts during regional workshops, on the basis of satisfying one or more of eight criteria that capture critical aspects of marine mammal biology, ecology and population structure. Candidate IMMAs undergo independent scientific review prior to being accepted, and then are publicly available via a searchable and downloadable database and a dedicated online e-Atlas. Between 2016 and 2021, eight expert workshops - engaging more than 300 experts - have resulted in the identification of 173 IMMAs located in 90 countries or territories, across a third of the globe. IMMAs identified to date provide important habitats for 58 of the 131 recognized marine mammal species. Around two-thirds of all IMMAs (65%) were identified on the basis of important habitat for a marine mammal species that is threatened on the IUCN Red List. Approximately 61% of IMMA surface areas occur within Exclusive Economic Zone waters, while 39% fall within areas beyond national jurisdiction. The Task Force undertook implementation planning exercises for IMMAs in Palau (Micronesia), the Andaman Islands (India) and the Bazaruto Archipelago and Inhambane Bay (Mozambique), engaging with a range of stakeholders including government and management bodies. IMMAs are increasingly being utilized in environmental impact assessments, marine planning exercises and in international, national and supra-regional conservation, policy and management initiatives, including the Convention on Migratory Species and Convention on Biological Diversity, as well as the design and management of Marine Protected Areas (MPAs) and the extension of MPA networks. The Task Force is working toward completing a global network of IMMAs that will contribute the scientific information needed to fulfill the current collective goal of protecting 30% of the ocean by 2030.Publisher PDFPeer reviewe

Estimating cetacean density and abundance in the Central and Western Mediterranean Sea through aerial surveys : implications for management

The equipment for data collection was that used during the EU LIFE Nature programme, project LIFE04NAT/GB/000245 project ‘‘Small Cetaceans in the European Atlantic and North Sea (SCANS-II)’’, funded in 2006.Systematic, effective monitoring of animal population parameters underpins successful conservation strategy and wildlife management, but it is often neglected in many regions, including much of the Mediterranean Sea. Nonetheless, a series of systematic multispecies aerial surveys was carried out in the seas around Italy to gather important baseline information on cetacean occurrence, distribution and abundance. The monitored areas included the Pelagos Sanctuary, the Tyrrhenian Sea, portions of the Seas of Corsica and Sardinia, the Ionian Seas as well as the Gulf of Taranto. Overall, approximately 48,000 km were flown in either spring, summer and winter between 2009–2014, covering an area of 444,621 km2. The most commonly observed species were the striped dolphin and the fin whale, with 975 and 83 recorded sightings, respectively. Other sighted cetacean species were the common bottlenose dolphin, the Risso's dolphin, the sperm whale, the pilot whale and the Cuvier's beaked whale. Uncorrected model- and design-based estimates of density and abundance for striped dolphins and fin whales were produced, resulting in a best estimate (model-based) of around 95,000 striped dolphins (CV=11.6%; 95% CI=92,900–120,300) occurring in the Pelagos Sanctuary, Central Tyrrhenian and Western Seas of Corsica and Sardinia combined area in summer 2010. Estimates were also obtained for each individual study region and year. An initial attempt to estimate perception bias for striped dolphins is also provided. The preferred summer 2010 uncorrected best estimate (design-based) for the same areas for fin whales was around 665 (CV=33.1%; 95% CI=350–1,260). Estimates are also provided for the individual study regions and years. The results represent baseline data to develop efficient, long-term, systematic monitoring programmes, essential to evaluate trends, as required by a number of national and international frameworks, and stress the need to ensure that surveys are undertaken regularly and at a sufficient spatial scale. The management implications of the results are discussed also in light of a possible decline of fin whales abundance over the period from the mid-1990s to the present. Further work to understand changes in distribution and to allow for improved spatial models is emphasized.PostprintPeer reviewe

Monitoring Winter and Summer Abundance of Cetaceans in the Pelagos Sanctuary (Northwestern Mediterranean Sea) Through Aerial Surveys

Systematic long-term monitoring of abundance is essential to inform conservation measures and evaluate their effectiveness. To instigate such work in the Pelagos Sanctuary in the Mediterranean, two aerial surveys were conducted in winter and summer 2009. A total of 467 (131 in winter, 336 in summer) sightings of 7 species was made. Sample sizes were sufficient to estimate abundance of fin whales in summer (148; 95% CI = 87–254) and striped dolphins in winter (19,462; 95% CI = 12 939–29 273) and in summer (38 488; 95% CI = 27 447–53 968). Numbers of animals within the Sanctuary are significantly higher in summer, when human activities and thus potential population level impacts are highest. Comparisons with data from past shipboard surveys suggest an appreciable decrease in fin whales within the Sanctuary area and an appreciable increase in striped dolphins. Aerial surveys proved to be more efficient than ship surveys, allowing more robust estimates, with smaller CIs and CVs. These results provide essential baseline data for this marine protected area and continued regular surveys will allow the effectiveness of the MPA in terms of cetacean conservation to be evaluated and inform future management measures. The collected data may also be crucial in assessing whether ship strikes, one of the main causes of death for fin whales in the Mediterranean, are affecting the Mediterranean population

Distribution patterns of marine megafauna density in the Mediterranean Sea assessed through the ACCOBAMS Survey Initiative (ASI)

The ACCOBAMS Survey Initiative (ASI) is the first synoptic large-scale survey of the entire ACCOBAMS Area and as such it plays a key role in filling the current gaps in our biological and ecological knowledge of large vertebrate species occurring in the region. Data gathered during the ASI were analyzed in a distance sampling surface-modelling framework to assess the summer distribution, densities and patterns, as well as to investigate the correlates of these parameters, for large vertebrate species and taxa in the Mediterranean Basin. Static and dynamic explanatory variables, including water depth (m), distance to depth contours (km), distance to canyons and seabed slope (km), sea surface temperature (°C), mixed layer depth (m) and levels of chlorophyll-a (mg/l), were considered to predict density and compute its variance spatially at a resolution of 10x10 km. A strong longitudinal gradient from low densities in the east to high densities in the west is shared by most taxa. In addition, several taxa also showed a less marked latitudinal gradient varying in direction according to species, and finally, a few of them exhibited patchy distributions

Large‐scale modelling of deep‐diving cetacean habitats

Versión del editor5,14