Fish–environment Associations in the Coastal Waters of Andros Island, The Bahamas

Synopsis We surveyed fish communities and corresponding environmental conditions at three broadly similar coastal sites of eastern Andros Island, The Bahamas over a summer–winter–summer sequence to assess the relationship between detailed environmental features and fish species patterns. Environmental variables included covers of various benthic flora components, benthic flora diversity, floral canopy height, micro-crustacean diversity and density, water temperature, extent of destructive land-use and extent of invasion by human-introduced exotic terrestrial plants. Correspondence analysis (CA) indicated that spatial (site) differences in environmental characteristics were greater than temporal (seasonal) differences. Detrended canonical correspondence analysis (DCCA) was used to assess the strength of relationships between the environmental characteristics and the distribution patterns of 25 fish species. Environmental features deemed to be most important in influencing fish species patterns included benthic flora canopy height, extent of invasion by exotic terrestrial plants, cover of Batophora oerstedii, cover of Thalassia testudinum, turf cover, water temperature, micro-crustacean diversity, and micro-crustacean density. Based upon similarities in distribution patterns, fish species formed four clusters which, ultimately, reflected similarities in species’ feeding habits and preferences for habitats that likely maximize foraging success. We conclude that fish distribution patterns are related to environmental characteristics, and that anthropogenic coastal activity, by influencing coastal benthic characteristics, may influence the distribution and abundances of fish species in coastal habitats.     

Freshwater diatom and macroinvertebrate diversity of coastal permanent ponds along a gradient of human impact in a Mediterranean eco-region

Mediterranean coastal areas are characterised by heavily transformed landscapes and an ever-increasing number of ponds are subjected to strong alterations. Although benthic diatoms and macroinvertebrates are widely used as indicators in freshwater ecosystems, little is still known about the diatom communities of lowland freshwater ponds in the Mediterranean region, and, furthermore, there are few macroinvertebrate-based methods to assess their ecological quality, especially in Italy. This article undertakes an analysis of benthic diatom and macroinvertebrate communities of permanent freshwater ponds, selected along a gradient of anthropogenic pressures, to identify community indicators (taxa and/or metrics) useful to evaluate the effect of human impacts. A series of 21 ponds were sampled along Tyrrhenian coast in central Italy. Five of these ponds, in a good conservations status and surrounded by woodland were selected as ‘reference sites’ for macroinvertebrates and epipelic diatoms. The remaining sixteen ponds were located in an agricultural landscape subject to different levels of human impact. The total number of macroinvertebrate taxa found in each pond was significantly higher in reference sites than in both the intermediate and heavily degraded ones, whereas the diatom species richness did not result in a good community variable to evaluate the pond ecological quality. The analysis revealed a substantial difference among the compositions of diatom communities between reference ponds and degraded ponds. The former were characterised by the presence of several species belonging to genera, such as Pinnularia sp., Eunotia sp., Stauroneis sp., Neidium sp., all of which were mostly absent from degraded ponds. Furthermore, the taxonomic richnesses of some macroinvetebrate groups (Odonata, Ephemeroptera, Trichoptera, Coleoptera), and taxa composition attributes of macroinvertebrate communities (total abundance, percentages of top three dominant taxa, percentages of Pleidae, Ancylidae, Hirudinea, Hydracarina) significantly correlated with variables linked with anthropogenic pressures. The results of the investigation suggested that diatoms tended more to reflect water chemistry through changes in community structure, whereas invertebrates responded to physical habitat changes primarily through changes in taxonomic richness. The methodologies developed for the analysis of freshwater benthic diatom and macroinvertebrate communities may have a considerable potential as a tool for assessing the ecological status of this type of water body, complying with the European Union Water Framework Directive 2000/60/EC. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. Guest editors: B. Oertli, R. Cereghino, A. Hull & R. Miracle Pond Conservation: From Science to Practice. 3rd Conference of the European Pond Conservation Network, Valencia, Spain, 14–16 May 2008     

The coastal fringe: Habitats threatened through global warming

Summary

Vegetation of the coastal fringe of Scotland (sea cliffs, dunes and salt marshes out to the depth limit of benthic algae and seagrasses) was subject to repeated cycles of glaciation, with low values of temperature, sea level and atmospheric CO₂, alternating with interglacials with higher temperature, sea level and atmospheric CO₂. The glaciations occasioned migrations of hundreds of kilometres south, and tens of metres downshore, to appropriate temperatures and zones on the shore. Losses of species from Scotland's coastal fringe flora as a result of these assaults are poorly documented, and direct evidence from fossils is lacking for seaweeds; more certainly, the present native coastal fringe flora must have managed to survive the last glacial-interglacial cycle although presumably not in Scotland. This does not necessarily mean that the coastal fringe species can withstand the current anthropogenic greenhouse effect (global warming) in which CO₂ partial pressure started to increase in about 1800, with subsequent increases in temperature and sea level, since the upper limits of the excursions of these three environmental factors during the last glacial- interglacial cycle may soon be exceeded. Furthermore, the rate of increase of these factors may be greater than that found in the glacial-interglacial transitions. Coastal fringe vegetation may also be threatened by more local anthropogenic actions, e.g. physical modification of the habitat by coastal defences against sea level increase, inputs of chemical pollutants, and direct harvesting of native plants or introduction of exotics. It is clear that, when the perturbation is removed, the vegetation can be substantially restored at least under present environmental conditions. Scottish botanists, while not able unaided to influence the global threats, can and should take action to minimize local anthropogenic threats, and monitor, and respond flexibly to, the response of the vegetation to the global and local changes.     

Transport and accumulation of sediment and contaminants in the Lagoon of Kuršiųmarios (Lithuania) and Baltic Sea

In this paper an overview is given of earlier work on transport, deposition AND transformation of suspended matter, and contaminants (metals, hydrocarbons) in Lithuanian coastal waters as well as in other parts of the Baltic Sea. The Lithuanian river Nemunas dischargesc. 600.10⁶ kg suspended matter into the Kuršių Marios Lagoon annually, of which two thirds are accumulated in the lagoon. The remainder is exported to the Baltic Sea through the Klaipéda Strait influencing biological activity in the coastal zone. Sedimentation rate in Kuršių Marios Lagoon is estimated at 3.2 mm y⁻¹. In the last 50 years the surface area of the lagoon decreased by 0.7 km² y⁻¹. Concentration profiles of metals and hydrocarbons were measured in the Kuršių Marios Lagoon, the Baltic proper, and in the Gulf of Finland. Among hydrocarbons both anthropogenic and compounds from natural sources are present. It is argued that correct interpretation of concentration horizons in sediment may be hampered by various processes,e. g. early sedimentogenesis and diagenesis, and cyclic salinity changes in the Baltic Sea.     

The effects of a colony of the Armenian gull (<Emphasis Type="Italic">Larus armeniacus</Emphasis> Buturlin) on zooplankton in the Lake Sevan littoral zone (Armenia)

The zooplankton of the open and semi-protected parts of Lake Sevan littoral zones that have been affected by the products of vital activity of the colony of the Armenian gull (Larus armeniacus Buturlin) were studied. It was shown that in the open coastal area the number of species is higher as compared to a similar reference site. However, the impact of wave-driven mixing of the water resulted in the lack of significant changes in the number and biomass of invertebrates at the compared observation sites. At the semi-protected part, the number of species, as well as the number and biomass of zooplankton, are significantly higher compared to the reference site. At the nesting area at both types of shoals copepods compose the basis of the zooplankton number and biomass, with Calanoida being part of the dominant complex. At the reference sites of the open shoal Copepoda also prevail; at the semi-protected sites, it is Cladocera that prevail. The basic differences between the effect of the products of the birds’ vital activities and anthropogenic eutrophication on zooplankton were revealed.     

In hot water: effects of climate change on Vibrio–human interactions

Sea level rise and the anthropogenic warming of the world's oceans is not only an environmental tragedy, but these changes also result in a significant threat to public health. Along with coastal flooding and the encroachment of saltwater farther inland comes an increased risk of human interaction with pathogenic Vibrio species, such as Vibrio cholerae, V. vulnificus and V. parahaemolyticus. This minireview examines the current literature for updates on the climatic changes and practices that impact the location and duration of the presence of Vibrio spp., as well as the infection routes, trends and virulence factors of these highly successful pathogens. Finally, an overview of current treatments and methods for the mitigation of both oral and cutaneous exposures are presented.     

In situ collection of endangered arbuscular mychorrhizal fungi in a Mediterranean UNESCO Biosphere Reserve

We report the establishment of the first in situ collection of beneficial symbiotic microorganisms (arbuscular mycorrhizal fungi) in the world, located in an integrally protected area of coastal sand dunes, within the UNESCO Biosphere Reserve “Selva Pisana”, in Tuscany, Italy. In this collection the genus Scutellospora, which has been reported to be threatened by anthropogenic disturbance, was a regular component of Ammophila arenaria and Helichrysum stoechas rhizospheres, and was represented by two species: Scutellospora fulgida and Scutellospora persica. Such species were morphologically identified and molecularly characterised by SSU and ITS sequence analyses. The establishment of an in situ collection of Scutellospora species in a protected area, where anthropogenic impact is under control of national and international authorities, is important for the conservation of rare and endangered microorganisms, representing a precious resource for future generations.     

Spatio-temporal variations of the zooplankton abundance and composition in a West African tropical coastal lagoon (Grand-Lahou,Côte d’Ivoire)

Zooplankton constitutes a sensitive tool for monitoring environmental changes in coastal lagoons; however, the available information on zooplankton communities is not sufficient to optimize their rational management. The relationships between zooplankton distribution and environmental factors were studied in a tropical lagoon to test whether the indicator properties of zooplankton assemblages could be used to monitor water quality, in a context of expected eutrophication provoked by an increasing anthropogenic activity. Twenty-one (21) stations were sampled monthly from January to December 2004. The community was composed of 65 taxa including Copepoda, Rotifera, and Cladocera. Copepoda was the most abundant group (81% of total numbers). The main zooplankton species were Oithona brevicornis, Acartia clausi, and Brachionus plicatilis. The highest zooplankton abundance (171–175 ind. l⁻¹) was recorded during the long, dry season (February–April) and the lowest (40–45 ind. l⁻¹) during the rainy and the flood periods (June–July). At a spatial level, the lowest abundance was observed in the estuarine zone. During the dry seasons (December–April and August–September), marine zooplankton taxa were abundant near the channel of Grand-Lahou, and brackish water taxa dominated in the other sites. Multivariate analyses (Co-inertia) showed that the composition of zooplanktonic communities and their spatio-temporal variations were mainly controlled by salinity variations closely linked to the climatic and hydrological context. The role of the trophic state on zooplankton communities could not be clearly evidenced. Our results and a comparison with previous studies in the neighboring, highly polluted Ebrié Lagoon suggest that the ratio between Oithona and Acartia abundance could be used as biological indicator for the water quality. Handling editor: S. I. Dodson     

Trace metals in marine,brackish and freshwater prawns (Crustacea,Decapoda) from northeast Algeria

The concentrations of the trace metals Zn, Cu, Fe, Cd and Pb were measured in four caridean decapods; Atyaephyra desmaresti, Palaemonetes varians, Parapenaeus longirostris and Aristeus antennatus, from freshwater , estuarine and marine habitats in northeast Algeria variably affected by anthropogenic metal contamination. The two coastal species (P. longirostris and A. antennatus) are a food source for the local population. Accumulated metal concentrations varied interspecifically, and intraspecifically between sites and between seasons, except in the case of Aristeus antennatus. The fresh and brackish water species (Atyaephyra desmaresti and Palaemonetes varians) accumulated more Cd and Pb than their marine counterparts. Results are discussed with respect to anthropogenic inputs and the environmental conditions of the regions studied.     

Effects of Urbanization-Induced Environmental Changes on Ecosystem Functioning in the Phoenix Metropolitan Region,USA

Abstract Urban ecosystems are profoundly modified by human activities and thereby provide a unique “natural laboratory” to study potential ecosystem responses to anthropogenic environmental changes. Because urban environments are now affected by urban heat islands, carbon dioxide domes, and high-level nitrogen deposition, to some extent they portend the future of the global ecosystem. Urbanization in the metropolitan region of Phoenix, Arizona (USA) has resulted in pronounced changes in air temperature (T _air), atmospheric CO₂ concentration, and nitrogen deposition (N_dep). In this study, we used a process-based ecosystem model to explore how the Larrea tridentata dominated Sonoran Desert ecosystem may respond to these urbanization-induced environmental changes. We found that water availability controls the magnitude and pattern of responses of the desert ecosystem to elevated CO₂, air temperature, N deposition and their combinations. Urbanization effects were much stronger in wet years than normal and dry years. At the ecosystem level, aboveground net primary productivity (ANPP) and soil organic matter (SOM) both increased with increasing CO₂ and N_dep individually and in combinations with changes in T _air. Soil N (N_soil) responded positively to increased N deposition and air temperature, but negatively to elevated CO₂. Correspondingly, ANPP and SOM of the Larrea ecosystem decreased along the urban–suburban–wildland gradient, whereas N_soil peaked in the suburban area. At the plant functional type (FT) level, ANPP generally responded positively to elevated CO₂ and N_dep, but negatively to increased T _air. C₃ winter annuals showed a greater ANPP response to higher CO₂ levels (>420 ppm) than shrubs, which could lead over the long term to changes in species composition, because competition among functional groups is strong for resources such as soil water and nutrients. Overall, the combined effects of the three environmental factors depended on rainfall variability and nonlinear interactions within and between plant functional types and environmental factors. We intend to use these simulation results as working hypotheses to guide our field experiments and observations. Experimental testing of these hypotheses through this process should improve our understanding of urban ecosystems under increasing environmental stresses.     

Basin elevation and salinity changes: late Holocene development of two freshwater lakes at the Karelian White Sea coast,northwest Russia as reflected in their sediments

In this paleolimnological multi-proxy study, anthropogenic influences and salinity changes of the northwest Russian lakes Erchovskye Ozero East (ESE) and Erchovskye Ozero West (ESW) were assessed using diatoms, pollen and other microfossils from ²¹⁰Pb-dated sediment cores. Both lakes are situated on the Fennoscandian Shield in direct vicinity to the White Sea coast, a region that is still subject to isostatic land uplift processes today. The analyses showed that both lakes evolved from typical saltwater-dominated coastal waters to freshwater lakes within the last two centuries. Salinity was found to be the determining environmental factor for the aquatic biota whereas no significant anthropogenic influences on the lakes could be detected. The decreasing salinity in both lakes was caused by basin elevation and isolation due to isostatic rebound of the Fennoscandian Shield. A hypothetical land uplift rate of 5.7 mm yr⁻¹ was calculated based on data from the sediment cores analysed. Guest editors: K. Buczkó, J. Korponai, J. Padisák & S. W. Starratt Palaeolimnological Proxies as Tools of Environmental Reconstruction in Fresh Water     

Migratory decisions in birds: extent of genetic versus environmental control

Migration is one of the most spectacular of animal behaviors and is prevalent across a broad array of taxa. In birds, we know much about the physiological basis of how birds migrate, but less about the relative contribution of genetic versus environmental factors in controlling migratory tendency. To evaluate the extent to which migratory decisions are genetically determined, we examined whether individual western burrowing owls (Athene cunicularia hypugaea) change their migratory tendency from one year to the next at two sites in southern Arizona. We also evaluated the heritability of migratory decisions by using logistic regression to examine the association between the migratory tendency of burrowing owl parents and their offspring. The probability of migrating decreased with age in both sexes and adult males were less migratory than females. Individual owls sometimes changed their migratory tendency from one year to the next, but changes were one-directional: adults that were residents during winter 2004–2005 remained residents the following winter, but 47% of adults that were migrants in winter 2004–2005 became residents the following winter. We found no evidence for an association between the migratory tendency of hatch-year owls and their male or female parents. Migratory tendency of hatch-year owls did not differ between years, study sites or sexes or vary by hatching date. Experimental provision of supplemental food did not affect these relationships. All of our results suggest that heritability of migratory tendency in burrowing owls is low, and that intraspecific variation in migratory tendency is likely due to: (1) environmental factors, or (2) a combination of environmental factors and non-additive genetic variation. The fact that an individual’s migratory tendency can change across years implies that widespread anthropogenic changes (i.e., climate change or changes in land use) could potentially cause widespread changes in the migratory tendency of birds.     

Changes in phenology of the locust tree (Robinia pseudoacacia L.) in Hungary

 Intense research is being carried out on climate variability and change and the estimation and detection of anthropogenic effects. In addition to statistical methods, the use of plants, as biological indicators is becoming more popular as they are sensitive to environmental conditions. In this article we compare maps of the flowering dates of the locust tree (Robinia pseudoacacia L.) for three different time intervals between 1851 and 1994. The maps revealed noticeable shifts of dates, of approximately 3–8 days, towards earlier flowering. This change is related to the average temperature of spring (15 March–15 May), via a simple statistical model that is accurate enough to be able to quantify phenological changes and to calculate the corresponding warming. The model developed can estimate spring mean temperature using phenological data from R. pseudoacacia L. with an accuracy of 0.2° C. Estimates of mean temperature based on phenological changes are compared to climatic series. This comparison emphasizes the possibility of using R. pseudoacacia. L. as a bio-indicator. Estimates of temperature changes are also given. Received: 5 August 1996 / Revised: 14 April 1997 / Accepted: 11 November 1997     

Realized distribution patterns of crowned lemurs (Eulemur coronatus) within a human-dominated forest fragment in northern Madagascar

Due to the impact of anthropogenic activities on forest extent and integrity across Madagascar, it is increasingly necessary to assess how endangered lemur populations inhabiting human-dominated forest fragments can effectively sustain themselves ecologically. Our research addresses this concern by exploring how the distribution patterns of a small population of crowned lemurs (Eulemur coronatus), occupying a degraded forest fragment at Oronjia Forest New Protected Area in northern Madagascar, are impacted by the availability of key ecological and anthropogenic factors. We hypothesize that the distribution of E. coronatus within the fragment is limited by the availability of critical ecological resources and conditions and the intensity of anthropogenic features and activities. To examine this, we used MaxEnt to develop a species distribution model using presence-only occurrence records and 10 independent background covariates detailing the site's ecological and anthropogenic aspects. The results indicate that the realized distribution patterns of E. coronatus within human-dominated forest fragments are strongly associated with sections of forest that contain sparsely and sporadically distributed resources, such as freshwater and continuous hardwood vegetation. We conclude that the distribution of E. coronatus at Oronjia is shaped by their need to maximize foraging opportunities in a degraded forest landscape where they are subject to both environmental and anthropogenic stressors.     

Environmental factors and ground disturbance affecting the composition of species and functional traits of ground layer lichens on grey dunes and dune heaths of Estonia

A unique, species‐rich and endangered lichen biota can be found on European coastal and inland sand dunes. However, it is increasingly affected by natural succession as well as by anthropogenic disturbances. We studied lichen diversity on the grey dunes and dune heaths of coastal and inland regions of Estonia. A total of 28 study plots were investigated; in each 0.1 ha study plot general environmental variables and anthropogenic disturbances were described and all epigeic lichen species were identified. We found 66 lichenized fungus (lichen) species, including several rare and ten red‐listed lichens. Multivariate analysis (DCA, CCA) was performed to examine gradients in species composition and to relate variation in species data to environmental factors. In addition, we used redundancy analysis (RDA) to relate variation in species’ trait composition to environmental factors. Species composition on grey dunes differed significantly from that on dune heaths. The characteristic species for grey dunes are, besides several Cladonia species, foliose lichens, e.g. Hypogymnia physodes, Parmelia sulcata and Peltigera spp. Also species’ traits composition was different for either habitat, indicating that sorediate lichens, foliose lichens, lichens with cyanobacterium as the main photobiont, and sparsely branched Cladonia species dominate on grey dunes, while esorediate, green‐algal, crustose and richly branched fruticose lichens are common on dune heaths. Soil pH was the most essential environmental variable for determining both species composition and species’ traits composition. The composition of lichen species was also significantly influenced by forest closeness, soil Mg content and cover of bare sand; the effect of ground disturbances was low compared to the effect of these environmental factors. To protect and conserve the species‐rich lichen biota, it is necessary to protect the dune habitats from building activity, to avoid overtrampling in recreation areas and to regularly remove shrubs and trees.     

Salmonella spp., Vibrio spp., Clostridium perfringens, and Plesiomonas shigelloides in Marine and Freshwater Invertebrates from Coastal California Ecosystems

The coastal ecosystems of California are highly utilized by humans and animals, but the ecology of fecal bacteria at the land–sea interface is not well understood. This study evaluated the distribution of potentially pathogenic bacteria in invertebrates from linked marine, estuarine, and freshwater ecosystems in central California. A variety of filter-feeding clams, mussels, worms, and crab tissues were selectively cultured for Salmonella spp., Campylobacter spp., Escherichia coli-O157, Clostridium perfringens, Plesiomonas shigelloides, and Vibrio spp. A longitudinal study assessed environmental risk factors for detecting these bacterial species in sentinel mussel batches. Putative risk factors included mussel collection near higher risk areas for livestock or human sewage exposure, adjacent human population density, season, recent precipitation, water temperature, water type, bivalve type, and freshwater outflow exposure. Bacteria detected in invertebrates included Salmonella spp., C. perfringens, P. shigelloides, Vibrio cholerae, Vibrio parahaemolyticus, and Vibrio alginolyticus. Overall, 80% of mussel batches were culture positive for at least one of the bacterial species, although the pathogens Campylobacter, E. coli-O157, and Salmonella were not detected. Many of the same bacterial species were also cultured from upstream estuarine and riverine invertebrates. Exposure to human sewage sources, recent precipitation, and water temperature were significant risk factors for bacterial detection in sentinel mussel batches. These findings are consistent with the hypothesis that filter-feeding invertebrates along the coast concentrate fecal bacteria flowing from land to sea and show that the relationships between anthropogenic effects on coastal ecosystems and the environmental niches of fecal bacteria are complex and dynamic.     

Risso’s dolphins (<Emphasis Type="Italic">Grampus griseus</Emphasis>) in UK waters are differentiated from a population in the Mediterranean Sea and genetically less diverse

The Risso’s dolphin (Grampus griseus) has a worldwide distribution, but little is known about their population genetic structure. Local coastal populations are never known to be abundant, and are sometimes under anthropogenic impact. Therefore the question of regional differentiation by genetic drift and overall diversity levels is of conservation interest. Here we present preliminary data that clearly indicate genetic differentiation and lower genetic diversity of a population sampled in UK waters (primarily from the Western Isles, Scotland) compared to a Mediterranean sample. Significant differentiation was found in comparison with a sample from the Mediterranean for both microsatellite DNA markers (F _ST = 0.0296) and mtDNA sequence data (F _ST = 0.260; ϕ _ST = 0.542). Allelic diversity was lower in the UK for nearly all loci.     

Variability of key biological parameters of round sardinella Sardinella aurita and the effects of environmental changes

We examined growth rates and reproductive characteristics of Sardinella aurita off Senegal and other coastal areas over a 20 year period (1995–2014) to determine how they relate to variations in environmental characteristics of coastal waters. Based on fish length-frequency data and a coastal upwelling index, we found that S. aurita recruitment tends to occur during the periods of most intensive upwelling (March–April off Senegal). Peak reproduction corresponds to periods of low sea-surface temperature (in February or March). The sex ratio was remarkably consistent during the 30 year study period and so was not affected by environmental changes. We hypothesise that S. aurita takes advantage of the higher zooplankton productivity that occurs in coastal waters when upwelling brings nutrient-rich water to the surface (i.e., it increases its growth rate and accumulates energy reserves for spawning). Growth performance appears to be strongly dependent on environmental conditions. The timing of spawning seems to occur when food (zooplankton) is most available for supplying the energy requirements needed by adults for spawning and early development of larvae. Environmental changes seem to have a significant effect on S. aurita growth and reproduction, which endorses their high phenotypic plasticity.     

Relative importance of human activities and climate driving common murre population trends in the Northwest Atlantic

Seabird populations are affected by environmental and anthropogenic influences on a global scale. Many population-level responses to climate change have been shown, yet few studies have addressed the additive and/or relative impact of environmental and anthropogenic influences on seabird populations. Using a mixed model approach, we analyzed the trends in plot counts of common murres (Uria aalge) from a Low Arctic colony at Cape St. Mary’s, Newfoundland, across 26 years (1980–2006). We tested for associations between population change and various environmental and anthropogenic covariates: water temperature, winter North Atlantic Oscillation, hunting mortality, oil pollution, by-catch in fishing gear, and visitor disturbance. The number of murres occupying central plots decreased from 1980 to 1989 and increased from 1990 to 2006. Annual changes in the population were negatively associated with the estimated number of murres killed in the Newfoundland murre hunt and the high numbers killed in the early 1980s likely caused the observed population decline. The large number of gillnets set in Newfoundland waters during the 1980s, and associated incidence of drowning through by-catch, probably also contributed to the observed decline. Though a centennially significant cold-water perturbation in 1991 forced a regime shift in pelagic food webs, the effect of ocean climate variability on the population was not obvious. We conclude that management efforts should focus on assessing and mitigating the effects of human-induced influences and consider the potential additive effects of climate change.     

Predicting the cover and richness of intertidal macroalgae in remote areas: a case study in the Antarctic Peninsula

Antarctica is an iconic region for scientific explorations as it is remote and a critical component of the global climate system. Recent climate change causes a dramatic retreat of ice in Antarctica with associated impacts to its coastal ecosystem. These anthropogenic impacts have a potential to increase habitat availability for Antarctic intertidal assemblages. Assessing the extent and ecological consequences of these changes requires us to develop accurate biotic baselines and quantitative predictive tools. In this study, we demonstrated that satellite‐based remote sensing, when used jointly with in situ ground‐truthing and machine learning algorithms, provides a powerful tool to predict the cover and richness of intertidal macroalgae. The salient finding was that the Sentinel‐based remote sensing described a significant proportion of variability in the cover and richness of Antarctic macroalgae. The highest performing models were for macroalgal richness and the cover of green algae as opposed to the model of brown and red algal cover. When expanding the geographical range of the ground‐truthing, even involving only a few sample points, it becomes possible to potentially map other Antarctic intertidal macroalgal habitats and monitor their dynamics. This is a significant milestone as logistical constraints are an integral part of the Antarctic expeditions. The method has also a potential in other remote coastal areas where extensive in situ mapping is not feasible.