Eco-Ethology Research Unit

Maintenance work on the harbor of Setúbal, in Portugal, required the removal of a 14-m deep rocky outcrop at the ship maneuver area, using about 35 kg of Gelamonite, a nitroglycerin-based highexplosive. This important harbor is located in the Sado estuary, a biologically rich environment and an important feeding area for a resident community of bottlenose dolphins. Using different safe range calculation models, a mitigation and monitoring plan was developed that minimized the risks of these underwater explosions for the dolphins. At our monitoring station, at 2 km from the demolition site, acoustic pressure levels in excess of 170 dB re 1 lPa (root-mean-square) were measured. Samples of dead fish collected at the site were indicative of shock trauma from the blasts.

In the Southern Hemisphere, humpback whales Megaptera novaeangliae feed in Antarctic waters during the austral summer and migrate to their breeding grounds in subtropical and tropical waters during the winter. Historical whaling records suggest that the Archipelago of São Tomé and Príncipe, located in the Gulf of Guinea, serves as a possible breeding ground. In order to investigate the temporal occurrence and group composition of humpback whales around São Tomé Island, annual surveys were conducted during the breeding season between 2002 and 2006. A total of 186 boat-based surveys took place during this period. Data collected during each sighting included geographical positions, group size, group composition and behavioural classifications. Of the 66 groups encountered, mother/ calf pairs made up a large proportion (65.15%), followed by solitary individuals (15.15%). Mother/calf pairs were seen in the region into November and resightings of identified animals indicate periods of occupancy that extended over three weeks. Few behaviours typically associated with mating activity were observed. Given the high percentage of mother/calf pairs, sometimes with very young calves, and the low frequency of mating activity, the waters of São Tomé may primarily serve as a calving and nursing or resting area for humpback whales.

The purpose of this article is to present the information available on the feeding behaviour and diet of bottlenose dolphins resident in the Sado estuary, Portugal. Bottlenose dolphins are opportunistic feeders, with a diversified diet that includes crustaceans, cephalopods, pelagic and benthonic fish, according to availability and abundance. The direct observation of feeding behaviours, supported by photographic and video records, allowed the identification of some of the dolphin prey species in this area, namely the European eel, the mullets, the common cuttlefish and the octopus. A list of the most frequent bottlenose dolphin prey species around the world was compared to the fish and cephalopod species occurring in the Sado estuary. This comparison enabled to list species that are probably preyed upon by the local dolphins. Observed foraging behaviour was more frequent in the shallower parts of the study area, where it may be easier to find and capture prey.

Acoustical geographic variation is common in widely distributed species and it is already described for several taxa, at various scales. In cetaceans, intraspecific variation in acoustic repertoires has been linked to ecological factors, geographical barriers, and social processes. For the common bottlenose dolphin (Tursiops truncatus), studies on acoustic variability are scarce, focus on a single signal type—whistles and on the influence of environmental variables. Here, we analyze the acoustic emissions of nine bottlenose dolphin populations across the Atlantic Ocean and the Mediterranean Sea, and identify common signal types and acoustic variants to assess repertoires’ (dis)similarity. Overall, these dolphins present a rich acoustic repertoire, with 24 distinct signal sub-types including: whistles, burst-pulsed sounds, brays and bangs. Acoustic divergence was observed only in social signals, suggesting the relevance of cultural transmission in geographic variation. The repertoire...

Acoustic call sequences are important components of vocal repertoires for many animal species. Bottlenose dolphins (Tursiops truncatus) produce a wide variety of vocalizations, in different behavioural contexts, including some conspicuous vocal sequences-the 'bray series'. The occurrence of brays is still insufficiently documented, contextually and geographically, and the specific functions of these multi-unit emissions are yet to be understood. Here, acoustic emissions produced by bottlenose dolphins in the Sado estuary, Portugal, were used to provide a structural characterization of the discrete elements that compose the bray series. Information theory techniques were applied to analyse bray sequences and explore the complexity of these calls. Log-frequency analysis, based on bout criterion interval, confirmed the bout structure of the bray series. A first-order Markov model revealed a distinct pattern of emission for the bray series' elements, with uneven transitions between elements. The order in these sequential emissions was not random and consecutive decreases in higher order entropy values support the notion of a well-defined structure in the bray series. The key features of animal signal sequences here portrayed suggest the presence of relevant information content and highlight the complexity of the bottlenose dolphin's acoustic repertoire.

Although navigation is common in many animals, only a few perform true navigation, meaning that they have the ability to return to a given place by relying on indirect cues obtained at the release site (i.e., by relying on information from a ''map and compass'' mechanism). The common intertidal fish, Lipophrys pholis, is thought to have homing abilities through a mechanism that primarily makes use of familiar landmarks (i.e., piloting). Anecdotal reports that individuals return to their home pools after release at unfamiliar sites suggest that L. pholis might use cues collected at the release site to find their way back (i.e., they might use map and compass information). Using a completely artificial setup, we tested the homing abilities of L. pholis as a function of age, sex, and familiarity with the release site. The findings showed that motivation for homing is present only in the adult phase and is independent of sex and/or familiarity with the release site. Moreover, adults released at a completely unfamiliar place oriented themselves in a direction roughly similar to that of their home pools. The fact that L. pholis were tested in a complete artificial environment means that hydrodynamic cues can be excluded as playing a role in this process and restricts the candidate options (e.g., magnetic cues). The ability to perform navigation based on a ''map and compass'' mechanism raises many interesting questions about the learning process, once these individuals have restricted home ranges during their lives. In vertebrate navigation, the cues used during the navigation process are a question of debate, and L. pholis offers an outstanding model to test hypotheses and ultimately provide answers.

Biogeographic transition zones in marine temperate systems are often hotspots of biodiversity, with high levels of resilience to short-term climate shifts due to naturally occurring cyclic oscillations of oceanographic conditions. However, these environments are likely vulnerable to a steady global warming scenario in which these cyclical conditions could be disrupted. Here, we evaluate how changes in local oceanography affect the structure of rocky reef fish assemblages over a period of 50 yr in a biogeographic transition zone. Using a 12 yr time series of rocky reef fish assemblage structure, we identified the set of oceanographic variables that most influenced assemblage dynamics. Descriptive and predictive models (multivariate regression trees) were compared to observed data using the area under the curve. Winter northward wind stress and sea surface temperature (SST) were the most important drivers of change in assemblage structure. Only warmer years had indicator species with warm-temperate or tropical affinities. A fish assemblage 'tropicalization' index was developed in response to both local-spatial resolution and short-term environmental variation (1993−2011), and to regional spatial resolution and long-term SST (1960−2012). Predictive modelling for the last 50 yr revealed that species with tropical affinities have increased in frequency compared to cold-temperate species, coinciding with the trend of increasing mean winter SST. Since the mid-1980s, warm-temperate and tropical species have responded rapidly to more frequent warm winters, suggesting that species distributions are shifting polewards. Our results support a hypothesis that cold species retreat more slowly than the advance of warm species. We discuss the importance of transition zones as 'barometers' of climate change.

Marine protected areas (MPAs) are a global conservation and management tool to enhance the resilience of linked social-ecological systems with the aim of conserving biodiversity and providing ecosystem services for sustainable use. However, MPAs implemented worldwide include a large variety of zoning and management schemes from single to multiple-zoning and from no-take to multiple-use areas. The current IUCN categorisation of MPAs is based on management objectives which many times have a significant mismatch to regulations causing a strong uncertainty when evaluating global MPAs effectiveness. A novel global classification system for MPAs based on regulations of uses as an alternative or complementing the current IUCN system of categories is presented. Scores for uses weighted by their potential impact on biodiversity were built. Each zone within a MPA was scored and an MPA index integrates the zone scores. This system classifies MPAs as well as each MPA zone individually, is globally applicable and unambiguously discriminates the impacts of uses.

Current international commitments on ocean protection targets include protecting 10% of the ocean through marine protected areas (MPAs) until 2020, while also complying with efficiency and equity requirements. This has led to a race to designate large MPAs, but despite the valid marine conservation efforts, conferring adequate protection is still at risk. While fully protected areas are considered the most efficient tools to effectively protect the integrity of ecosystems, most existing or proposed MPAs are far from being fully or strongly protected. Portugal, with the 20th largest EEZ of the world is well positioned to lead ocean conservation efforts and provides a suitable case study for analysis of protection conferred by existing MPAs. To this end, Portuguese MPAs were assessed according to different types of classification systems and it was found that most MPAs confer little or no additional protection compared to outside areas. The results differ according to the classification system used, revealing the importance of finding a common system for evaluating progress in ocean conservation. The relevance of adequately labelling and understanding the levels of protection in place is demonstrated. Not differentiating the type of protection conferred by MPA regulations, while rushing towards international targets, may give a potentially false impression to society.

The perceptions of fishers towards the Arrábida Marine Park, a marine protected area (MPA) in the west coast of Portugal, were studied through face-to-face interviews in two different moments of the MPA life cycle. Fishers' perceptions about the MPA and the impact it had on the fishing activity over time were identified just before the full implementation of the zoning and regulations of the management plan and 10 years later. This study aimed to investigate fishers' knowledge, acceptance and perceptions about the MPA changed with time, if support for the MPA was linked to the impact of the MPA on the fishing activity, and if fishers' perceptions about the impact of the MPA on the fishing activity match with local landings trends. Results show that although knowledge about the marine park significantly improved over time, fishers' acceptance did not. A decrease on fishers' support was not substantial but occurred. Issues such as the disagreement with regulations reinforced concerns raised during the implementation of the marine park, particularly in relation to the top-down decision-making, which commonly confers minor participation, recognition and legitimacy to fishers. Apparently, fisheries benefits were still not perceived by local fishers, though they are central for fishers' support. Further, the perceived negative impacts of the park seemed to be more related to social aspects and individual interests than to impacts on catches. Addressing adequate management, enforcement and participation of local fishers is still possible and are advocated here as to contribute to the expected socioecological outcomes and respective support, leading to the future successful performance of the Arrábida Marine Park. Assessing fishers' perceptions towards an MPA over time is central and should be included on periodical socioecological monitoring and inform an effective adaptive management.

Marine Protected Areas (MPAs) require effective indicators to assess their performance, in compliance with the goals of relevant national and international commitments. Achieving and prioritizing shortlists of multidisciplinary indicators demands a significant effort from specialists to depict the multiple conservation and socioeconomic interests, and the large complexity of natural systems. The present paper describes a structured expert-based methodology (process and outputs) to co-define a list of multidisciplinary MPA performance indicators. This work was promoted by the management authority of coastal MPAs in mainland Portugal to gather a consensual and feasible list of indicators that would guide the design of a future national monitoring program. Hence, Portuguese coastal MPAs served as a case study to develop such a process between 2019 and 2020. In the end, participants (1) agreed on a shortlist of prioritized indicators (i.e., environmental, governance, and socioeconomic i...

Inshore bays are key foraging grounds for immature green turtles Chelonia mydas. At these confined areas, capture−mark−recapture (CMR) programs generate valuable information
that can be used to estimate vital rates, essential for the effective conservation of this endangered species. We compiled the CMR history profiles of 273 individuals from 13 yr of in-water surveys and employed the Cormack-Jolly-Seber model to estimate the survival probabilities of green turtles in 2 neritic bays at Culebra municipality, Puerto Rico. The CMR profiles were grouped into 2 size classes: juvenile and subadult. No adults were captured during the study. We found no significant
differences in survival probability between the green turtles occupying each bay. We also assessed the survival probability of fibropapillomatosis (FP)-afflicted turtles versus FP-free turtles
and found no significant differences among these groups. However, there was a significant difference in survival between the 2 size classes. Juveniles showed a higher survival probability (0.8322, 95% CI = 0.7875 to 0.8690) than subadults (0.5290, 95% CI = 0.3851 to 0.6682). The low survival of subadults is  potentially biased by the permanent emigration of some of these individuals. Previous studies have shown that larger immatures leave shallow protected bays and occupy deeper open waters, sometimes associated with adults. Juveniles seem to be resident, and their survival rate can serve as a reference value for viability analysis. This is the first study on the survival of green turtles in the West Indies.

Understanding conservation needs relies on robust estimates of key population parameters, such as survival, abundance and somatic growth. We investigated the somatic growth and abundance dynamics of 2 aggregations of immature green turtles, at Tortuga Bay and Puerto Manglar (Culebra, Puerto Rico), throughout 15 yr of capture-mark-recaptures. We used nonlinear models to investigate the effects of carapace length, sampling year, growth interval and the presence of fibropapillomas on growth rates, and used the size-specific growth rate function to estimate how long turtles remain at each bay. Abundances were estimated and compared with time-specific growth rate functions, to infer density-dependency effects on somatic growth rates, and trends in abundance were evaluated by fitting generalized linear models. We found foraging site specific growth rates and report the highest mean somatic growth rate for green turtles in the wild (6.1 ± 1.7 cm yr−1, at Puerto Manglar). The size-specific growth rate function was monotonic at both sites, with growth rates declining continuously with increasing carapace length. We inferred
minimum ages at maturity of 14 and 22 yr, for Puerto Manglar and Tortuga Bay turtles, respectively. Throughout the 15 yr of this study there was a positive trend in aggregation size at Puerto Manglar (mean annual increase of 10.9%), which was not observed at Tortuga Bay. Our study highlights the influence of geography and habitat quality on somatic growth rates, and delivers robust demographic estimates valuable for local and regional assessments of the conservation status of the green turtle.