Key Marine Areas Research Articles

Spatio-temporal patterns of northern gannet abundance in a migratory and wintering area

In marine ecosystems, seabird populations are well monitored, thus allowing their use as indicators of system fluctuations at multiple spatio-temporal scales. Population abundance estimates are essential features of any conservation and management measures and initiatives. Population abundances can be used to delineate the distribution range and foraging grounds of species during both breeding and non-breeding periods, with multi-annual monitoring allowing for the inspection of the temporal variability within key marine areas. Taking advantage of long-term monitoring schemes, we examined the annual abundance patterns of the northern gannet Morus bassanus in its southern European migratory flyway. Here, the presence of a topographical feature (i.e. a submarine canyon system) could influence physical processes (e.g. upwelling, alongshore currents, and riverine inputs), thus oceanographically differentiating canyon and shelf ecosystems within a spatially restricted marine area. We assessed seasonal and long-term trend fluctuations of monthly northern gannet abundance using Generalized Additive Mixed Models, yielding only a strong seasonal effect. Moreover, we jointly tested the effect of the phenology and the spatial domain (canyon versus shelf) on northern gannet abundance using Generalised Linear Mixed Models, accounting for the excess of zeros. Northern gannet abundance was higher during the pre-winter and post-winter migration, corresponding to its southward and northward movements in the NE Atlantic, respectively. The effect of the canyon was only detected during the post-winter migration. By age, adult northern gannets were more abundant in some periods of the year (from October to March, including the pre-winter migration, the wintering and the post-winter migration), whereas juveniles and immatures were especially abundant during the pre-winter period. Our results could provide quantitative baseline information of northern gannet spatio-temporal patterns in a migratory and wintering area important for both research and conservation efforts, given the high conservation value of the area within the Natura 2000 network.

An adaptive method for identifying marine areas of high conservation priority.

Identifying priority areas for biodiversity conservation is particularly challenging in the marine environment due to the open and dynamic nature of the ocean, the paucity of information on species distribution, and the necessary balance between marine biodiversity conservation and essential supporting services such as seafood provision. We used the Patagonian seabird breeding community as a case study to propose an integrated and adaptive method for delimiting key marine areas for conservation. Priority areas were defined through a free decision-support tool (Marxan) that included projected at-sea distributions of seabirds (approximately 2,225,000 individuals of 14 species); BirdLife Important Bird and Biodiversity Areas (IBAs) for pelagic bird species; and the economic costs of potential regulations in fishing practices. The proposed reserve network encompassed approximately 300,000 km2 that was largely concentrated in northern and southern inshore and northern and central offshore regions. This reserve network exceeded the minimum threshold of 20% conservation of the abundance of each species proposed by the World Parks Congress. Based on marine currents in the study area, we further identified the 3 primary water masses that may influence areas of conservation priority through water inflow. Our reserve network may benefit from enhanced marine productivity in these highly connected areas, but they may be threatened by human impacts such as marine pollution. Our method of reserve network design is an important advance with respect to the more classical approaches based on criteria defined for one or a few species and may be particularly useful when information on spatial patterns is data deficient. Our approach also accommodates addition of new information on seabird distribution and population dynamics, human activities, and alterations in the marine environment.

Using a multi-model ensemble forecasting approach to identify key marine protected areas for seabirds in the Portuguese coast

Marine Protected Areas (MPAs) have been established across all marine environments, though their coherence and effectiveness in protecting umbrella species remains unclear. We used a multi-model ensemble forecasting approach, on 8 years of at-sea censuses of 30 seabird species to identify candidate MPAs in the Portuguese coast, prioritizing important areas for their conservation based on their occurrence and distribution. We overlapped the outputs generated by the Ensemble Ecological Niche Models (EENMs) with layers representing important environmental stressors (fishing intensity, ship density and oil pollution risk), and calculated loss in conservation value using them as cost layers. Three key marine areas were identified along the Portuguese coast: For breeders, there was a key marine area encompassing the Tagus and Sado estuaries and Berlengas archipelago; for non-breeders and migratory species two important areas were identified in the Northern and Southern coast. The key marine area identified in the Northern coast is characterized by high productivity and biodiversity, and can be affected by oil pollution from the refineries and the intensive ship traffic in this area. Also, the area identified in the Southern coast of Portugal for migratory seabirds overlaps extensively with areas of high fishing activity. Our results show that the Important Bird and Biodiversity Areas (IBAs) established along the Portuguese coast protect more than a third of the areas that we prioritized for breeding species and the official MPAs near 65% of the same areas. In contrast, current IBAs and national legislation protect less than 4% of the coastal areas that we prioritize for non-breeding species in this study. Our study, combining multi-species distribution with environmental constraints induced by human activities, allowed us to assess the coherence of the Portuguese marine planning and identify candidate areas to join the Portuguese network of marine protected areas. Our results, employing data from annual at-sea surveys together with the human stressors known to affect the Portuguese coast, proved to be an extremely useful strategy to identify spatial conservation areas along the Portuguese coast as well as to access the adequacy and consistency of those areas. Despite the constraints of this demanding approach, we are confident that our study provides a reliable strategy to inform marine conservation efforts and management planning in similar coastal environments elsewhere, characterized by strong coastal upwelling movements.

Identification of candidate pelagic marine protected areas through a seabird seasonal‐, multispecific‐ and extinction risk‐based approach

AbstractWith increasing pressure on the oceans from environmental change, there has been a global call for improved protection of marine ecosystems through the implementation of marine protected areas (MPAs). Here, we used species distribution modelling (SDM) of tracking data from 14 seabird species to identify key marine areas in the southwest Atlantic Ocean, valuing areas based on seabird species occurrence, seasonality and extinction risk. We also compared overlaps between the outputs generated by the SDM and layers representing important human threats (fishing intensity, ship density, plastic and oil pollution, ocean acidification), and calculated loss in conservation value using fishing and ship density as cost layers. The key marine areas were located on the southern Patagonian Shelf, overlapping extensively with areas of high fishing activity, and did not change seasonally, while seasonal areas were located off south and southeast Brazil and overlapped with areas of high plastic pollution and ocean acidification. Non‐seasonal key areas were located off northeast Brazil on an area of high biodiversity, and with relatively low human impacts. We found support for the use of seasonal areas depending on the seabird assemblage used, because there was a loss in conservation value for the seasonal compared to the non‐seasonal approach when using ‘cost’ layers. Our approach, accounting for seasonal changes in seabird assemblages and their risk of extinction, identified additional candidate areas for incorporation in the network of pelagic MPAs.

Identification of key marine areas for conservation based on satellite tracking of post-nesting migrating green turtles (Chelonia mydas)

The green turtle (Chelonia mydas) is classified as an endangered species on the IUCN Red List since 1986. This species is especially threatened in South America due to bycatch by fisheries along the northeastern coasts. It is particularly crucial to identify specific marine areas for conservation measures to safeguard green turtle rookeries in Suriname and French Guiana. Our study provides valuable information to attain this goal, describing the satellite tracking of post-nesting migration routes used by 16 green turtles fitted with Argos/GPS Fastloc satellite tags at the end of the nesting season. The data we obtained show a single migratory corridor: all the turtles followed a similar eastward route along the Guianan and the Brazilian coast. The GPS signal was lost for two individuals a few weeks after tracking commenced, suggesting that they were caught by fishermen. Thirteen turtles reached the coast of the state of Ceará (Brazil), where they spent at least one month. One turtle continued 700km further to the coastal regions of Natal and Recife (Brazil), which are known feeding areas of the green turtle populations nesting on Ascension Island. The migratory corridor is essentially narrow, with a width of 22km for most of the distance covered. It constitutes a major dynamic link between the nesting and feeding areas and crosses three Regional Management Units of the Atlantic basin. Since green turtles face a high risk of being caught in fishing nets, measures of protection should be implemented along this corridor.

Combining Methods to Describe Important Marine Habitats for Top Predators: Application to Identify Biological Hotspots in Tropical Waters.

In tropical waters resources are usually scarce and patchy, and predatory species generally show specific adaptations for foraging. Tropical seabirds often forage in association with sub-surface predators that create feeding opportunities by bringing prey close to the surface, and the birds often aggregate in large multispecific flocks. Here we hypothesize that frigatebirds, a tropical seabird adapted to foraging with low energetic costs, could be a good predictor of the distribution of their associated predatory species, including other seabirds (e.g. boobies, terns) and subsurface predators (e.g., dolphins, tunas). To test this hypothesis, we compared distribution patterns of marine predators in the Mozambique Channel based on a long-term dataset of both vessel- and aerial surveys, as well as tracking data of frigatebirds. By developing species distribution models (SDMs), we identified key marine areas for tropical predators in relation to contemporaneous oceanographic features to investigate multi-species spatial overlap areas and identify predator hotspots in the Mozambique Channel. SDMs reasonably matched observed patterns and both static (e.g. bathymetry) and dynamic (e.g. Chlorophyll a concentration and sea surface temperature) factors were important explaining predator distribution patterns. We found that the distribution of frigatebirds included the distributions of the associated species. The central part of the channel appeared to be the best habitat for the four groups of species considered in this study (frigatebirds, brown terns, boobies and sub-surface predators).

Building of the criteria for determining of key marine areas of the Vietnam national plans for biodiversity conservation

In this paper, the construction method outlined criteria identify key sensitive areas (hot spots) of interest of marine ecosystems in the planning of Biodiversity Conservation in Vietnam. Set up criteria for determining the influence of the nature and impact of humans on the ecosystem of the national park of marine ecosystems was studied (ecosystem of mangroves, coral reefs, sea grass, upwelling ecosystems). The research methodology was based on: Rapid Assessment Method participatory (PRA); Inventory method matrix environment (Environmental Inventory) Dirk et al. and UNEP; Methods inherited, information collected through workshops, documentation gathering, investigation, networking internets. The results of this study have built the criteria for determining the sensitivity of concern identified through the index sensitivity to resource Biodiversity (Biodiversity Vulnerability Index-BVI) or the pressure of self- spiders and humans to biodiversity through the establishment of criteria, evaluation criteria and case studies. These are the initial results of the index determines the sensitivity index of BVIh to evaluate the effects of human impact and natural conditions in the forest ecosystem should be considered in Biodiversity Conservation Planning in our country.

Comparison of methods for determining key marine areas from tracking data

There is an urgent need to identify key marine areas for conservation, particularly in the high seas. A range of techniques have been applied to tracking data from higher predators, particularly seabirds and pinnipeds, to determine the areas of greatest use. This study compared three commonly used methods—kernel, first-passage time and state-space modelling—and a new approach, minimum displacement rate, for the analysis of data from the wandering albatross Diomedea exulans of Bird Island, South Georgia, tracked during the chick-rearing period. Applied to a single track, these four models identified similar marine areas as important. The greatest similarity in areas identified occurred when model assumptions were shared (such as slow speed indicating spatial preference) even when methods modelled these assumptions differently (e.g. Bayesian inference versus cumulative density surface). A gridded overlap approach applied to all tracks revealed core areas not apparent from results of any single analysis. The gridded approach also revealed spatial overlap between methods based on different assumptions (e.g. minimum displacement rate and kernel analysis) and between individuals. Although areas identified as important by kernel and first-passage time analysis of a single track were biased towards resting locations during darkness, this does not negate the requirement for their protection. Using the gridded overlap approach, two distinct core regions were identified for the wandering albatross; one close to the breeding colony and another 800 km to the North–West in the high seas. This convenient and pragmatic approach could be applied to large data sets and across species for the identification of a network of candidate marine protected areas in coastal and pelagic waters.

Protecting Persistent Dynamic Oceanographic Features: Transboundary Conservation Efforts Are Needed for the Critically Endangered Balearic Shearwater

The protection of key areas for biodiversity at sea is not as widespread as on land and research investment is necessary to identify biodiversity hotspots in the open ocean. Spatially explicit conservation measures such as the creation of representative networks of marine protected areas (MPAs) is a critical step towards the conservation and management of marine ecosystems, as well as to improve public awareness. Conservation efforts in ecologically rich and threatened ecosystems are specially needed. This is particularly urgent for the Mediterranean marine biodiversity, which includes highly mobile marine vertebrates. Here, we studied the at sea distribution of one of the most endangered Mediterranean seabird, the critically endangered Balearic shearwater Puffinus mauretanicus. Present knowledge, from vessel-based surveys, suggests that this species has a coastal distribution over the productive Iberian shelf in relation to the distribution of their main prey, small pelagic fish. We used miniaturised satellite transmitters to determine the key marine areas of the southern population of Balearic shearwaters breeding on Eivissa and spot the spatial connections between breeding and key marine areas. Our tracking study indicates that Balearic shearwaters do not only forage along the Iberian continental shelf but also in more distant marine areas along the North African coast, in particular W of Algeria, but also NE coast of Morocco. Birds recurrently visit these shelf areas at the end of the breeding season. Species distribution modelling identified chlorophyll a as the most important environmental variable in defining those oceanographic features characterizing their key habitats in the western Mediterranean. We identified persistent oceanographic features across time series available in the study area and discuss our results within the current conservation scenario in relation to the ecology of the species.

Combining vessel-based surveys and tracking data to identify key marine areas for seabirds

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 391:183-197 (2009) - DOI: https://doi.org/10.3354/meps08124 Combining vessel-based surveys and tracking data to identify key marine areas for seabirds M. Louzao1,5,*, J. Bécares2, B. Rodríguez2, K .D. Hyrenbach3, A. Ruiz4, J. M. Arcos2 1Centre d’Etudes Biologiques de Chizé, CNRS, 79360 Villiers en Bois, France 2Sociedad Española de Ornitología/BirdLife, C/Múrcia 2-8, local 13, 08026 Barcelona, Spain 3Duke University Marine Laboratory, 135 Duke Marine Laboratory Road, Beaufort, North Carolina 28516, USA 4Sociedad Española de Ornitología/BirdLife, C/Melquíades Biencinto 34, 28053 Madrid, Spain 5Present address: Helmholtz Centre for Environmental Research-UFZ, Permoserstraße 15, 04318 Leipzig, Germany *Email: maite.louzao@ufz.de ABSTRACT: An understanding of the distribution and habitat associations of far-ranging marine predators is being increasingly applied to protect these species from anthropogenic threats at sea (e.g. oil spills and fisheries bycatch). Within this framework, this research on Cory’s shearwater Calonectris diomedea integrates vessel-based survey and tracking data to provide 2 distinct, yet complementary, perspectives of the habitats of this species in the western Mediterranean during incubation in June and chick rearing in August of 2007. We used a hierarchical modelling approach to (1) delineate the foraging habitat of the species using vessel-based surveys and (2) identify its feeding habitat based on tracking data within the Information-Theoretic framework. Our habitat modelling analyses suggest that shearwaters respond to complex bio-physical coupling, illustrated by their association with frontal features and elevated ocean productivity. Our models yielded moderate predictions of Cory’s shearwater habitats within 2 distinct spatial scales. At the mesoscale, the foraging range of the species comprised the continental and insular shelf-slope waters of the Iberian Peninsula and the Balearic Islands, between the Gulf of Lions to the north and Cape Palos to the south. At the coarse scale, the tracking data highlighted important feeding areas within this larger foraging range: 3 continental shelf-slope ‘hotspots’—(1) Gulf of Lions, (2) Cape Creus–Barcelona–Ebro Delta and (3) Cape La Nao–Cape Palos; from north to south—as well as the insular shelf-slope areas around the Balearic Islands. These results match previous observations of the foraging range and feeding patterns of the species, and are consistent with the interpretation of the regional oceanography. This study highlights how the integration of tracking and vessel-based survey data can provide a wider understanding of the predictability of aggregation (i.e. hotspots) and the key oceanographic habitats of far-ranging seabirds at multiple spatial scales. Thus, complementary data integration is a step forward in conservation studies of far-ranging marine top predators. KEY WORDS: Calonectris diomedea · Cory’s shearwater · Feeding hotspot · Foraging range · Habitat modelling · Important Bird Area (IBA) · Information-Theoretic approach · Ocean remote sensing · Conservation · Western Mediterranean Full text in pdf format Supplementary material PreviousNextCite this article as: Louzao M, Bécares J, Rodríguez B, Hyrenbach KD, Ruiz A, Arcos JM (2009) Combining vessel-based surveys and tracking data to identify key marine areas for seabirds. Mar Ecol Prog Ser 391:183-197. https://doi.org/10.3354/meps08124Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 391. Online publication date: September 28, 2009 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2009 Inter-Research.

Evaluating the coastal environment for marine birds

The marine environment is being increasingly exploited by fisheries and the oil and gas industry. Conservationists urgently need the ability to identify the processes that determine patterns of abundance of marine species. We describe a preliminary Geographic Information System (GIS) in which spatial data on environmental variables (seabird colony locations, sea depth and seabed sediments) are integrated with realistic energy constraints faced by marine birds during the breeding season. A simple foraging model predicts the spatial variation in the quality of given locations as potential feeding sites under different feeding conditions and stages of the breeding cycle. We show how the approach can be used to help managers identify key marine areas and assess the impacts of environmental change or damage.