Designation of large expanses of the ocean as Marine Protected Area (MPA) is increasingly advocated and realised. The effectiveness of such MPAs, however, requires improvements to vessel monitoring and enforcement capability. In 2014 commercial fishing was excluded from the Ascension Island Exclusive Economic Zone (EEZ). In 2015, through updated regulations, a licenced fishery re-opened in the northern half of the EEZ while the southern half remained closed. To assess compliance with these closures and regulations, several promising satellite technologies (Satellite Automatic Identification System (S-AIS), Synthetic Aperture Radar (SAR), Vessel Monitoring System (VMS) of two vessels), were trialled alongside at-sea patrols. Use of SAR enabled assessment of ‘dark’ (non-AIS transmitting) vessels, the scope of whose activities are hardest to gauge. The high level of compliance with regulations observed, suggests the MPA may prove effective, yet a need for vigilance remains. Vessels aggregate near the EEZ border and a quarter of vessels tracked across three years exhibited S-AIS transmission gaps and present a heightened compliance risk. Use of remote, rather than local, expertise and infrastructure provide a blue-print and economies of scalefor replicating monitoring across similarly sized MPAs; particularly for large (>~ 25 m) vessels with metallic superstructures conducive to SAR detection. Funding ongoing monitoring in Ascension is challenged by current levels of license uptake, which provides insufficient offsetting revenue. Satellite-derived intelligence, can be used to set risk thresholds and trigger detailed investigations. Planning long-term monitoring must, however, incorporate adequate resources for follow-up, through patrols and correspondence with flag-states and fisheries management organisations.
Acoustic tagging is typically used to gather data on the spatial ecology of diverse marine taxa, informing questions about spatio-temporal attributes such as residency and home range, but detection data may also reveal unanticipated insights. Many species demonstrate predictable site fidelity, and so a sudden cessation of detections for multiple individuals may be evidence of an atypical event. During 2013 and 2014, we acoustically tagged 47 grey reef sharks (Carcharhinus amblyrhynchos) and 48 silvertip sharks (Carcharhinus albimarginatus) near reefs in the British Indian Ocean Territory (BIOT) Marine Protected Area (MPA). From March 2013 to November 2014 inclusive, tags were ‘lost’, i.e. permanently ceased to be detected within the monitoring area, at an average rate of 2.6 ± 1.0 tags per month. Between 1 and 10 December 2014, detection data suggest the near-simultaneous loss of 15 of the remaining 43 active tagged sharks, a monthly loss rate over five times higher than during the previous 21 months. Between 4 and 14 December of 2014, the BIOT patrol vessel encountered 17 vessels engaged in suspected illegal fishing in the northern BIOT MPA; such sightings averaged one per month during the previous 8 months. Two of these vessels were arrested with a total of 359 sharks on board, of which grey reef and silvertip sharks constituted 47% by number. The unusual and coincident peaks in tag loss and vessel sightings, and the catch composition of the arrested vessels, suggest illegal fishing as a plausible explanation for the unusual pattern in our detection data. A Cox proportional hazards model found that the presence of fishing vessels increased the risk of tag loss by a factor of 6.0 (95% CI 2.6–14.0, p < 0.001). Based on the number of vessels sighted and the average number of sharks on vessels arrested in BIOT during 2014, we conservatively estimate that over 2000 sharks may have been removed during the suspected fishing event. Based on average catch compositions, over 1000 would have been grey reef and silvertip sharks. Assuming a closed population mark-recapture model, over one-third of the locally resident reef sharks may have been removed from the monitoring area. The data suggest that even sporadic fishing events may have a marked impact on local reef shark populations, but also demonstrate the potential of electronic tagging a tool for detecting illegal or otherwise unreported fishing activity.
Increasingly studies are reporting sudden and dramatic changes in the structure and function of communities or ecosystems. The prevalence of these reports demonstrates the importance for management of being able to detect whether these have happened and, preferably, whether they are likely to occur. Ecological theory provides the rationale for why such changes occur and a variety of statistical indicators of approach that have generic properties have been developed. However, whether the theory has successfully translated into monitoring programmes is unknown. We searched the literature for guidelines that would drive design of monitoring programmes able to detect past and approaching tipping points and analysed marine monitoring programmes in New Zealand. We found very few guidelines in the ecological, environmental or monitoring literature, although both simulation and marine empirical studies suggest that within-year sampling increases the likelihood of detecting approaching tipping points. The combination of the need to monitor both small and medium scale temporal dynamics of multiple variables to detect tipping points meant that few marine monitoring programmes in New Zealand were fit for that purpose. Interestingly, we found many marine examples of studies detecting past and approaching TP with fewer data than was common in the theoretical literature. We, therefore, suggest that utilizing ecological knowledge is of paramount importance in designing and analyzing time-series monitoring for tipping points and increasing the certainty for short-term or infrequent datasets of whether a tipping point has occurred. As monitoring plays an important role in management of tipping points by providing supporting information for other locations about when and why a tipping point may occur, we believe that monitoring for tipping points should be promoted.
Nesting sea turtles appear to avoid brightly lit beaches and often turn back to sea prematurely when exposed to artificial light. Observations and experiments have noted that nesting turtles prefer darker areas where buildings and high dunes act as light barriers. As a result, sea turtles often nest on darker beaches, creating spatial concentrations of nests. Artificial nighttime light, or light pollution, has been quantified using a variety of methods. However, it has proven challenging to make accurate measurements of ambient light at fine scales and on smaller nesting beaches. Additionally, light has traditionally been measured from stationary tripods perpendicular to beach vegetation, disregarding the point of view of a nesting sea turtle. In the present study, nighttime ambient light conditions were assessed on three beaches in central North Carolina: a developed coastline of a barrier island, a nearby State Park on the same barrier island comprised of protected and undeveloped land, and a completely uninhabited wilderness on an adjacent barrier island in the Cape Lookout National Seashore. Using an autonomous terrestrial rover, high resolution light measurements (mag/arcsec2) were collected every minute with two ambient light sensors along transects on each beach. Spatial comparisons between ambient light and nesting density at and between these locations reveal that highest densities of nests occur in regions with lowest light levels, supporting the hypothesis that light pollution from coastal development may influence turtle nesting distribution. These results can be used to support ongoing management strategies to mitigate this pressing conservation issue.
Over 25 years ago the first satellite tracking studies of sea turtles were published. The technology and attachment methods have now come of age with long-term tracks over a year being commonplace and the ability to relay high resolution GPS locations via the Argos satellite system along with behavioral (e.g., diving and activity) and environmental (e.g., temperature) data. Early studies focused on breeding females because they come ashore to nest, allowing individuals to be restrained relatively easily for tag attachment. However, today the development of methods for the capture of turtles at sea are increasingly allowing studies on both adult male turtles as well as immature turtles as small as 11 cm carapace length. Here we review the extent of work after many thousands of individual turtles have been tracked. We consider the state-of-the-art equipment for satellite tracking turtles and how this technology is being used to tackle key questions. We highlight some of the emerging opportunities arising from improved spatial resolution of tracking, increased robustness and miniaturization of tags as well as increasing availability of environmental data. We highlight the huge potential for big-data studies to make use of the thousands of tracks that exist, although we discuss the long-standing challenges surrounding data accessibility.
Citizen science is an innovative approach that relies on non-specialists to monitor species and ecosystems over long time periods and vast geographical areas. Citizen science has been used extensively in marine science to monitor endangered species such as sharks and marine turtles, coral reefs and their associated fish species, marine mammals, invasive species and, more recently, coral bleaching and marine litter. Engaging people over the long term can be challenging but using social media, gamification, and emphasizing the value of volunteer contributions through data sharing, can help to keep communities motivated. In the Red Sea, there is enormous potential for using citizen science in monitoring endangered species and ecosystems due to the presence of a fleet of safari boats and dive centres going to sea daily. Engaging with this sector and creating long lasting partnerships for data collection through simple protocols could be a winning approach to obtain important information from remote areas and/or on rare species. In this chapter, we present the preliminary results of a citizen science program targeting marine turtles in their feeding grounds in the Egyptian Red Sea waters that was conducted from 2011 to 2013. During the study period 2,448 surveys were completed at 157 sites and included a total of 1,038 sightings of turtles. The most commonly observed species were hawksbill (Eretmochelys imbricata) and green (Chelonia mydas) turtles; however, rarer species, such as loggerhead (Caretta caretta) and olive ridley (Lepidochelys olivacea) turtles were also recorded. Among the sites that were monitored, some were considered as important for turtles (i.e., had a high probability of observing a turtle), while in others, turtles were not observed despite carrying out multiple surveys. Participants reported turtles of various sizes and ages with adults and sub-adults being the predominant observed age class. The presence of adults seemed to be related to the nesting season (May–September), which was also when the survey effort was higher. Adult male turtles were observed on various occasions, providing important input on their whereabouts during nesting and non-nesting seasons. Finally, participants detected behaviour that had not been previously described in the region, such as courting and mating. Results from TurtleWatch Egypt provided new insight in our knowledge of marine turtles in the Red Sea, especially from the largely under-studied feeding grounds.
Monitoring marine activities has always been a difficult task due to the vastness of the world's oceans. This inability to properly monitor both high seas and territorial zones alike has meant that illegal activities at sea have been able to flourish, from illegal fishing to human rights violations to maritime piracy. Lately, however, the rise of new methods of technological monitoring – from satellites to UAVs – has increased optimism that a better, technologically-aided method of ocean monitoring and governance may help to diminish the proliferation of these and other illegal activities. This paper considers the ways in which technological innovation has been proposed to help ocean monitoring and governance, and analyzes the extent to which the optimism over these new techniques is warranted.
This study was aimed at monitoring beach litter using an unmanned aerial vehicle (UAV) in the coastal city of Fuzhou, China. The data analysis shows that the optical images obtained by digital cameras on the UAV can help to identify and monitor beach litter using remote sensing and GIS technologies. The threshold method can effectively segment the UAV image in the beach area. It is useful for quickly monitoring the distribution of beach litter in the area of interest, and hence it can help to provide effective technical support for the investigation and assessment of coastal beach litter.
Anthropogenic marine debris is one of the major worldwide threats to marine ecosystems. The EU Marine Strategy Framework Directive (MSFD) has established a protocol for data collection on marine debris from the gut contents of the loggerhead sea turtle (Caretta caretta), and for determining assessment values of plastics for Good Environmental Status (GES). GES values are calculated as percent turtles having more than average plastic weight per turtle. In the present study, we quantify marine debris ingestion in 155 loggerhead sea turtles collected in the period 1995–2016 in waters of western Mediterranean (North-east Spain). The study aims (1) to update and standardize debris ingestion data available from this area, (2) to analyse this issue over two decades using Zero-altered (hurdle) models and (3) to provide new data to compare the only GES value available (off Italian waters). The composition of marine debris (occurrence and amounts of different categories) was similar to that found in other studies for the western Mediterranean and their amounts seem not to be an important threat to turtle survival in the region. Model results suggest that, in the study area, (a) period of stranding or capture, (b) turtle size and (c) latitude are significant predictors of anthropogenic debris ingestion (occurrence and amount) in turtles. The GES value for late juvenile turtles (CCL>40 cm) has decreased in the last ten years in the study area, and this is very similar to that obtained in Italian waters. We also provide a GES value for early juvenile turtles (CCL≤40 cm) for the first time. Recommendations arising from this study include ensuring use of (1) the standardized protocol proposed by the MSFD for assessing marine debris ingestion by loggerhead sea turtles and (2) the ecology of the turtles (neritic vs oceanic), rather than their size, to obtain GES values.
Citizen science projects are an advantageous method to carry out research in the marine environmental field, especially concerning high mobile and often elusive species like cetaceans, allowing the collection of data in wide spatial-temporal scale. This project aims to validate the feasibility and accuracy of cetacean monitoring program through the citizen science approach and to test the efficiency of this method to large scale study area. In this work data obtained by researchers monitoring were compared with data coming from citizen, which followed specifically developed protocol. Data collected were used to investigate the presence and distribution of bottlenose dolphins (Tursiops truncatus) in the Sicilian Channel and to evaluate the contribution of citizen scientist to improve knowledge about species, in this case for bottlenose dolphin a vulnerable species listed in the Annex II of Habitat Directive (92/43 CE). The results show that citizen dataset contributes to increase the distribution map of the 22% more than only research data were considered. Citizen science programme results useful to gain information in small areas not monitored by scientific programs, such as in this study, and they would be very useful if applied at large-scale. The promotion of citizen science programs in specified small areas could be helpful to cover unmonitored zones, to gain preliminary results and bridge the gap of knowledge about species occurrence and distribution. For this reason, citizen support might help competent authorities to answer to the environmental policies as Habitat Directive and Marine Strategy Framework Directive. This study is a demonstration of how citizen can encourage scientists to start long-term research project in not regularly monitored areas.