BDRI researchers address a wide range of questions to form a multi-dimensional picture of the marine megafauna behaviour and ecology and its relationship to the rest of the planet, including human society. The study of marine biodiversity is extraordinarily complex because of the diversity of organisms that inhabit the marine environment.

 

Areas of research

CETACEAN ECOLOGY

• This topic includes spatial analysis and creation of models from cetacean distribution data recorded in Atlantic waters (Galicia, Spain). Outcomes of these studies will provide more information on the distribution of cetacean species in Galicia, and about the impact of human activities on cetacean distribution. This coast is among the most productive oceanic regions in the world and is characterized by high biodiversity, productive fisheries and important aquaculture activities, all supported by the nutrient input due to coastal upwelling events. The Galician firths (known as Rías) on the North-western coast of Spain have been identified as an area of year-round presence of bottlenose dolphins and harbour porpoises and are thus a suitable area for placing possible special areas of conservations (SACs) under the EU Habitats Directive.

   

• More than 20 species of cetaceans have been recorded in Galician waters, the most abundant in the coastal rías are bottlenose dolphins (Tursiops truncatus), harbour porpoises (Phocoena phocoena) and short-beaked common dolphins (Delphinus delphis). Other species present in the area include Risso’s dolphins (Grampus griseus), striped dolphins (Stenella coeruleoalba), long-finned pilot whale (Globicephala melas), killer whales (Orcinus orca), sperm whales (Physeter macrocephalus), beaked whales (3 species), humpback whales (Megaptera novaeangliae), minke whales (Balaenoptera acutorostrata), sei whales (Balaenoptera borealis), fin whales (Balaenoptera physalus), and blue whales (Balaenoptera musculus). We also find Eurasian otters (Lutra lutra) in rivers and along the shoreline of Galician rías. Galicia is home to hundreds of species of birds, either permanently or seasonally and include several species of seagulls, cormorants, shags, gannets, auks, shearwaters, petrels, skuas, terns, herons, loons, and many more. A variety of conservation issues affect the marine life in Galician waters, many of which are related to human activity, such as the interaction with fisheries, (a significant cause of mortality), overfishing, aquaculture activities, oil spills, pollution, the effects of noise from shipping, military activity and tourism. The degree of impact of any human activity, varies considerably between different species and depends on their ecology, distribution and abundance.

 

 

CETACEAN BEHAVIOUR

This topic consists of the analysis of behavioural data (bottlenose dolphin, common dolphin, baleen whales, and/or harbour porpoises) recorded in Atlantic waters (Galicia, Spain). Human activities can influence the distribution of food resources, which may promote behavioural changes in the species as a response to fluctuations in the costs of feeding competition. Therefore, these types of studies present  information needed to examine the behavioural response of cetaceans affected by human activities in coastal waters (especially fisheries, aquaculture, and habitat modification). The study of cetacean behaviour also defines an important class of ecological relationships between individuals, their environment, and their nearby conspecifics. Outcomes of these studies will provide important information on individual and group behaviour, as well as information on the impact of human activities on marine mammal behaviour.

 

BOTTLENOSE DOLPHIN COMMUNICATION

This is the analysis of bio-acoustical and behavioural data recorded from study areas characterized by different levels of anthropogenic impact. Bioacoustics research provides important insights into animal behaviour. Dolphins (family: Delphinidae) are an extremely vocal mammalian family and vocal communication plays an important role in mediating social interactions. Most BDRI studies of delphinid vocalizations have concentrated on bottlenose dolphins, Tursiops truncatus (in the Mediterranean, Italy, and in the Atlantic Ocean, Spain) and Tursiops aduncus (in the Arabian Gulf, Abu Dhabi, UAE) but we have also started new studies on short-beaked dolphin and baleen whale communication in Atlantic waters. Most dolphin species can produce two primary types of sounds thought to play a role in social interactions: (i) tonal, frequency-modulated whistles, and (ii) rapid repetition rate “burst-pulse” click trains. As the complexity of bottlenose dolphin social organization is only matched by few species, their communication system merits profound investigation, despite the many methodological difficulties that are inherent to their aquatic life. These studies explore the use of social vocalizations in different contexts (feeding, socialising, travelling, resting) and look for geographic and contextual similarities in social sound use. Outcomes of these studies will provide more information on the function of specific social vocalisations,  influence of the environment and, in some cases, anthropogenic activities.

 



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DOLPHIN SOCIETY and MARK-RECAPTURE studies

Much of the research work is based upon repeat observations of individually-recognisable dolphins, providing data for a range of long-term and ongoing studies on the abundance, site fidelity, home range, social structure and behaviour of a population. Common bottlenose dolphins live in fission–fusion societies within which individuals associate in small groups that change in composition, often on a daily or hourly basis. This specific topic includes analysis of mark-recapture data from bottlenose dolphin and/or common dolphin groups recorded in Atlantic waters (Galicia, Spain) in order to estimate abundance, residency patterns, and social structure. Outcomes of these studies will provide more information about population abundance, dolphin society and, in some cases the impact caused by human activities.

 

SKIN PIGMENTATION AND BODY MARKS IN CETACEANS

This specific topic is analysis of photographic data of cetaceans recorded in Atlantic waters (Galicia, Spain), Mediterranean Sea, and in the Arabian Gulf. Outcomes of these studies will provide more information about cetacean external body conditions, taking into account intra- and inter-specific interactions, infections, diseases and in some cases the impact caused by human activities.

 

 

MARINE BIRD ECOLOGY

This topic includes spatial analysis and creation of models from data about marine birds recorded in Atlantic waters (Galicia, Spain). Galicia is home to hundreds of species of birds (both seasonally and year-round) and include several species of marine birds such as the Yellow-legged gull (Larus michahellis), Black-head gull (Chroicocephalus ridibundus), Mediterranean gull (Ichthyaetus melanocephalus), Great black-backed gull (Larus marinus), Lesser black-backed gull (Larus fuscus), Sabine's gull (Xema sabini), European shag (Phalacrocorax aristotelis), Great cormoran (Phalacrocorax carbo), Common tern (Sterna hirundo), Sandwich tern (Thalasseus sandvicensis), Northern gannet (Morus bassanus), Razorbill (Alca torda), Common guillemot (Uria aalge), Great skua (Stercorarius skua), Parasitic jaeger (Stercorarius parasiticus), Pomarine jaeger (Stercorarius pomarinus), Cory's shearwater (Calonectris borealis), Manx shearwater (Puffinus puffinus), Yelkouan shearwater (Puffinus yelkouan), Sooty shearwater (Ardenna grisea), Great shearwater (Puffinus gravis), Balearic shearwater (Puffinus mauretanicus), European storm petrel (Hydrobates pelagicus), Wilson's storm petrel (Oceanites oceanicus), Common scoter (Melanitta nigra), Northern fulmar (Fulmarus glacialis), Atlantic puffin (Fratercula arctica). Outcomes of these studies will provide more information about marine bird distribution and potential impacts caused by human activities.

 

FORAGING ECOLOGY OF EURASIAN OTTER

This is the study of the feeding ecology of  otters (Lutra lutra) in the Ría de Arousa (Galicia, Spain). Knowledge of the diet of a species is crucial in understanding its behaviour and ecology, and can also be used to assess the impact of potential behavioural changes or spatial use that may be associated with anthropogenic activities. Research into the feeding habits of otters  relies on the examination of spraint samples and the identification and measurement of hard parts such as fish otoliths and cephalopod beaks. This project aims to describe the diet composition of Eurasian otters in a coastal marine environment by conducting spraint analysis and visual observation of the individuals. The identification of each prey item to the species level along with size and mass estimates of prey will allow for a detailed description and comparison of diet composition as well as provide insight into the foraging behaviour and ecology of this mammal in a marine environment. Outcomes of these studies will provide more information about European otter ecology by studying the spraints and foraging behaviour.

 

 

 

BALAENATUR: MONITORING BALEEN WHALES IN GALICIAN WATERS

Since 2020, the BDRI is working on the project BALAENATUR, monitoring blue whales in relation to their migratory patterns, distribution and behaviour within the Galician continental shelf and in particular within Natura 2000 areas. This project is supported by the Fundación Biodiversidad of the Spanish Ministry for Ecological Transition and the Demographic Challenge. The results of this project will provide valuable information on blue, fin and sei whales in Galician waters, which is essential for the development of a Whale Recovery Plan in Spanish waters, as well as for optimising the management of Natura 2000 sites, and which can serve as a basis for decision-making for the conservation of these species.

 

 

MARINE MAMMAL RESEARCH AND CONSERVATION IN THE ARABIAN/PERSIAN GULF

BDRI researchers have coordinated with the Environmental Agency of Abu Dhabi since 2014, and participated in the first long-term research project to obtain accurate data on population estimates, distribution, potential threats and residence patterns of marine mammal species observed in the coastal waters of Abu-Dhabi (United Arab Emirates). The study area deserves area-based protection and should be a potential area for consideration by governments, intergovernmental organizations, conservation groups, and the general public. Our studies remark that this is an important year-round habitat for four sympatric species of marine mammals with a potential need for management and conservation: Indian ocean humpback dolphin Sousa chinensis (IUCN - Endangered), Indopacific bottlenose dolphin Tursiops aduncus (IUCN – Data Deficient), finless porpoise Neophocoena phocaenoides (IUCN - Vulnerable), and dugong, Dugong dugong (IUCN - Vulnerable. Moreover, other two marine mammal species, such as the orca (Orcinus orca) and long-beaked common dolphins (Delphinus capensis), were reported seasonally in the area. It is important to remark that these coastal waters are home to the largest population of Indian Ocean humpback dolphins that has been evaluated in the world and the largest population of dugongs known outside Australia. Results from our studies highlighted that the limited coastal range coupled with near-shore distribution make humpback dolphins, Indo-Pacific bottlenose dolphins, dugongs, and finless porpoises particularly vulnerable to mortality and traumatic injuries from heavy maritime traffic and gill-netting practices. Moreover, in this region, dredging, land reclamation, port and harbour construction, boat traffic, oil and gas exploration (including seismic surveying), development of nuclear plants, and other coastal development activities all occur, or are concentrated in this important coastal area, threatening the survival of all marine mammal species living within it.

 

 

In order to carry out research in Spanish waters the BDRI collaborates with several national and international institutions and has a special research permit delivered by the Spanish Government.

 

 

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