Dynamic body acceleration as a proxy to predict the cost of locomotion in bottlenose dolphins

Estimates of the energetic costs of locomotion (COL) at different activity levels are necessary to answer fundamental eco-physiological questions and to understand the impacts of anthropogenic disturbance to marine mammals. We combined estimates of energetic costs derived from breath-by-breath respirometry with measurements of overall dynamic body acceleration (ODBA) from biologging tags to validate ODBA as a proxy for COL in trained common bottlenose dolphins (Tursiops truncatus). We measured resting metabolic rate (RMR); mean individual RMR was 0.71-1.42 times that of a similarly sized terrestrial mammal and agreed with past measurements which used breath-by-breath and flow-through respirometry. We also measured energy expenditure during submerged swim trials, at primarily moderate exercise levels. We subtracted RMR to obtain COL, and normalized COL by body size to incorporate individual swimming efficiencies. We found both mass-specific energy expenditure and mass-specific COL were linearly related with ODBA. Measurements of activity level and cost of transport (the energy required to move a given distance) improve understanding of the costs of locomotion in marine mammals. The strength of the correlation between ODBA and COL varied among individuals, but the overall relationship can be used at a broad scale to estimate the energetic costs of disturbance, daily locomotion costs to build energy budgets, and investigate the costs of diving in free-ranging animals where bio-logging data are available. We propose that a similar approach could be applied to other cetacean species.

Using Case Studies to Investigate Cetacean Bycatch/Interaction Under-Reporting in Countries With Reporting Legislation

Accurate reporting of cetacean bycatch in/interaction with fishing gear in fisher logbooks would be of immense scientific value; however, despite some countries having mandatory reporting laws, logbook reporting is widely considered unreliable and cetacean catches are thought to be under-reported. Despite this widespread notion of logbook unreliability, under-reporting has rarely been quantified. For this study, initially we compiled the first comprehensive legislation summary for countries which have cetacean bycatch/interaction reporting laws. We then used data provided by government and research agencies in three case study countries (New Zealand, United States, and Iceland) to test for differences between logbook and observer reported cetacean bycatch. Comparisons were made using paired t-tests and Wilcoxon tests with a set alpha of 0.05. Overall, cetacean bycatch recorded by observers was higher than that from fisher logbooks by an average of 774% in trawls, 7348% in nets, and 1725% in hook and line gears. When combining all years of data available, fisher logbook cetacean catch per unit efforts or average number of individuals caught were significantly less than those from observer data for all gear types that could be examined in all countries, except for lining in New Zealand. Overall, there was significant under-reporting in the case study countries despite differences in geographic location, cetacean species and density and EEZ size, suggesting these results would likely be similar in many countries with comparable, well-developed fishing industries. Under-reporting in logbooks, despite laws, was clearly quantified and it is known that fishers have little incentive to report and have concerns over negative repercussions to the industry over bycatch issues. If logbook reporting is to continue in some fisheries, clearer legislation, simplified reporting using new technology (such as smartphone apps) and combination with electronic monitoring cameras to verify compliance may improve reporting accuracy. The introduction of electronic monitoring, given its lower cost compared to observer programs and high accuracy, may be the most viable option to obtain reliable cetacean bycatch estimates, and could be considered to replace logbook reporting altogether.

Diet-driven mercury contamination is associated with polar bear gut microbiota

The gut microbiota may modulate the disposition and toxicity of environmental contaminants within a host but, conversely, contaminants may also impact gut bacteria. Such contaminant-gut microbial connections, which could lead to alteration of host health, remain poorly known and are rarely studied in free-ranging wildlife. The polar bear (Ursus maritimus) is a long-lived, wide-ranging apex predator that feeds on a variety of high trophic position seal and cetacean species and, as such, is exposed to among the highest levels of biomagnifying contaminants of all Arctic species. Here, we investigate associations between mercury (THg; a key Arctic contaminant), diet, and the diversity and composition of the gut microbiota of polar bears inhabiting the southern Beaufort Sea, while accounting for host sex, age class and body condition. Bacterial diversity was negatively associated with seal consumption and mercury, a pattern seen for both Shannon and Inverse Simpson alpha diversity indices (adjusted R2 = 0.35, F1,18 = 8.00, P = 0.013 and adjusted R2 = 0.26, F1,18 = 6.04, P = 0.027, respectively). No association was found with sex, age class or body condition of polar bears. Bacteria known to either be involved in THg methylation or considered to be highly contaminant resistant, including Lactobacillales, Bacillales and Aeromonadales, were significantly more abundant in individuals that had higher THg concentrations. Conversely, individuals with higher THg concentrations showed a significantly lower abundance of Bacteroidales, a bacterial order that typically plays an important role in supporting host immune function by stimulating intraepithelial lymphocytes within the epithelial barrier. These associations between diet-acquired mercury and microbiota illustrate a potentially overlooked outcome of mercury accumulation in polar bears.

The Memories of Our Future: The Memories of Maūi

<p>This thesis proposes a way to re-inhabit and transform the adverse identity of an old offshore oil and gas platform. Located 35 kilometers off the West Coast of Taranaki, New Zealand, the Māui A Platform (also known as MPA) is transformed in this thesis design investigation into an Environmental Centre, a living retreat for ‘children’ (in fact, for adults who will be encouraged in the design to see life through the eyes of children). The intention is to generate knowledge and awareness about the environment. The Māui A and Māui B offshore oil and gas platforms are nearing the end of their economic lifespan. Globally, the current most common decommissioning method of oil platforms involves the use of explosives at the base of the jacket. The structure is then towed to shore and dismantled. The explosives leave scars not only on the landscape the platforms once inhabited; they critically damage the surrounding marine ecology, vast numbers of marine species. This is of severe concern for the marine life and ecosystems surrounding the Māui A & Māui B Platforms as they are located in an extremely sensitive marine area where over 30 percent of the world’s cetacean species inhabit or through which they frequently migrate. Only two of these marine mammal species are not listed as ‘species of concern’ in the New Zealand Threat Classification list. The future of these platforms does not need to cause more adversity to the environment, but rather can regenerate it. By re-purposing rather than exploding and dismantling these structures, this thesis aims to propose a way to re-inhabit the Māui A Platform and transform it into an educational retreat that enables further awareness, reconciliation, restoration, and protection of marine systems, environment, and threatened marine species. This thesis explores opportunities to create a closed circuit system as a means of providing food, fresh water, water treatment and energy for the platform. To achieve this regenerative solution in ways that will resonate with those who visit the Māui A Platform, this project enters the realm of the imagination. The imagination is fundamental to learning - hence the proposition that this design be framed as both mythological and experiential. Narrative design – story telling – is explored as a tool to connect sustainable awareness and consciousness as a means to help educate the beneficiaries of this world – our ‘children’. To encourage the adult visitors to fully recognise that the beneficiaries are indeed our children, the thesis investigation will design the new Environmental Centre through the eyes of the child. As a tool to enhance the historic narrative of the site and context, the design strategically frames traces of important or unnoticed elements or equipment of the Māui A Platform. In order to be understood and engaged with by ‘children’, this project enters the realm of the imagination enabling the design to be both mythological and experiential.</p>

The Memories of Our Future: The Memories of Maūi

<p>This thesis proposes a way to re-inhabit and transform the adverse identity of an old offshore oil and gas platform. Located 35 kilometers off the West Coast of Taranaki, New Zealand, the Māui A Platform (also known as MPA) is transformed in this thesis design investigation into an Environmental Centre, a living retreat for ‘children’ (in fact, for adults who will be encouraged in the design to see life through the eyes of children). The intention is to generate knowledge and awareness about the environment. The Māui A and Māui B offshore oil and gas platforms are nearing the end of their economic lifespan. Globally, the current most common decommissioning method of oil platforms involves the use of explosives at the base of the jacket. The structure is then towed to shore and dismantled. The explosives leave scars not only on the landscape the platforms once inhabited; they critically damage the surrounding marine ecology, vast numbers of marine species. This is of severe concern for the marine life and ecosystems surrounding the Māui A & Māui B Platforms as they are located in an extremely sensitive marine area where over 30 percent of the world’s cetacean species inhabit or through which they frequently migrate. Only two of these marine mammal species are not listed as ‘species of concern’ in the New Zealand Threat Classification list. The future of these platforms does not need to cause more adversity to the environment, but rather can regenerate it. By re-purposing rather than exploding and dismantling these structures, this thesis aims to propose a way to re-inhabit the Māui A Platform and transform it into an educational retreat that enables further awareness, reconciliation, restoration, and protection of marine systems, environment, and threatened marine species. This thesis explores opportunities to create a closed circuit system as a means of providing food, fresh water, water treatment and energy for the platform. To achieve this regenerative solution in ways that will resonate with those who visit the Māui A Platform, this project enters the realm of the imagination. The imagination is fundamental to learning - hence the proposition that this design be framed as both mythological and experiential. Narrative design – story telling – is explored as a tool to connect sustainable awareness and consciousness as a means to help educate the beneficiaries of this world – our ‘children’. To encourage the adult visitors to fully recognise that the beneficiaries are indeed our children, the thesis investigation will design the new Environmental Centre through the eyes of the child. As a tool to enhance the historic narrative of the site and context, the design strategically frames traces of important or unnoticed elements or equipment of the Māui A Platform. In order to be understood and engaged with by ‘children’, this project enters the realm of the imagination enabling the design to be both mythological and experiential.</p>

Bacteriological and histopathological findings in cetaceans that stranded in the Philippines from 2017 to 2018

The relatively high frequency of marine mammal stranding events in the Philippines provide many research opportunities. A select set of stranders (n = 21) from 2017 to 2018 were sampled for bacteriology and histopathology. Pertinent tissues and bacteria were collected from individuals representing eight cetacean species (i.e. Feresa attenuata, Kogia breviceps, Globicephala macrorhynchus, Grampus griseus, Lagenodelphis hosei, Peponocephala electra, Stenella attenuata and Stenella longirostris) and were subjected to histopathological examination and antibiotic resistance screening, respectively. The antibiotic resistance profiles of 24 bacteria (belonging to genera Escherichia, Enterobacter, Klebsiella, Proteus, and Shigella) that were isolated from four cetaceans were determined using 18 antibiotics. All 24 isolates were resistant to at least one antibiotic class, and 79.17% were classified as multiple antibiotic resistant (MAR). The MAR index values of isolates ranged from 0.06 to 0.39 with all the isolates resistant to erythromycin (100%; n = 24) and susceptible to imipenem, doripenem, ciprofloxacin, chloramphenicol, and gentamicin (100%; n = 24). The resistance profiles of these bacteria show the extent of antimicrobial resistance in the marine environment, and may inform medical management decisions during rehabilitation of stranded cetaceans. Due to inadequate gross descriptions and limited data gathered by the responders during the stranding events, the significance of histopathological lesions in association with disease diagnosis in each cetacean stranding or mortality remained inconclusive; however, these histopathological findings may be indicative or contributory to the resulting debility and stress during their strandings. The findings of the study demonstrate the challenges faced by cetacean species in the wild, such as but not limited to, biological pollution through land-sea movement of effluents, fisheries interactions, and anthropogenic activities.

Nutritional status and prey energy density govern reproductive success in a small cetacean

A variety of mammals suppress reproduction when they experience poor physical condition or environmental harshness. In many marine mammal species, reproductive impairment has been correlated to polychlorinated biphenyls (PCBs), the most frequently measured chemical pollutants, while the relative importance of other factors remains understudied. We investigate whether reproductively active females abandon investment in their foetus when conditions are poor, exemplified using an extensively studied cetacean species; the harbour porpoise (Phocoena phocoena). Data on disease, fat and muscle mass and diet obtained from necropsies in The Netherlands were used as proxies of health and nutritional status and related to pregnancy and foetal growth. This was combined with published life history parameters for 16 other areas to correlate to parameters reflecting environmental condition: mean energy density of prey constituting diets (MEDD), cumulative human impact and PCB contamination. Maternal nutritional status had significant effects on foetal size and females in poor health had lower probabilities of being pregnant and generally did not sustain pregnancy throughout gestation. Pregnancy rates across the Northern Hemisphere were best explained by MEDD. We demonstrate the importance of having undisturbed access to prey with high energy densities in determining reproductive success and ultimately population size for small cetaceans.

Interaction between sperm whales (Physeter macrocephalus) and northern bottlenose whales (Hyperoodon ampullatus) and deep-water trawlers in the Northwest Atlantic

Interactions between various cetacean species and fisheries are geographically widespread and diverse. Foraging in association with fishing activities may increase prey encounter rates and possibly increase the quantity and the quality of the food consumed. This paper describes interactions between benthic trawlers, targeting mainly Greenland halibut, and two whale species: sperm whales and northern bottlenose whales, in the eastern Grand Banks of the northwest Atlantic. Whale behaviors were compared during four trawling-related activities: preparing/ shooting the net, towing, hauling and transiting between fishing sites. Sperm whales and bottlenose whales were more likely to be observed during hauling. We observed probable feeding behavior of both species close to the surface at the end of hauling which suggests they are taking fish escaping from the cod end of the net when it is close to the surface. It is not clear whether feeding attempts are made during other phases of the trawling cycle. Ten sperm whales were photo-identified and six of these individuals were resighted on different days. Resights of individuals indicated that sperm whales could follow trawlers through several sets over of distances up to 234 km. While some individuals were observed to move between fishing grounds others remained within one fishing area for some time. By contrast, even though twenty-three bottlenose whales were photo-identified, there were no resights of individual whales. While northern bottlenose whales have been studied quite extensively in some adjacent areas, particularly off Nova Scotia, their behaviour and distribution within the Grand Banks fishing areas has not been well described. No matches were found between northern bottlenose whales in this study and photo-identification catalogues for the Scotian Shelf or the Arctic. Whether and how northern bottlenose whales found in this area are connected to other subpopulations remains unclear.

Patterns and Trends in Cetacean Occurrence Revealed by Shorewatch, a Land-Based Citizen Science Program in Scotland (United Kingdom)

Shorewatch is a citizen science project, managed by Whale and Dolphin Conservation (WDC), that records the occurrence of cetaceans during regular, standardized watches from a series of locations along the coast of Scotland (United Kingdom). Observer training and a clearly defined protocol help deliver a valuable source of information about cetacean occurrence and activity along the coast. Between 2005–2018, over 52000 watches generated over 11000 sightings of at least 18 cetacean species. Generalized Additive Models based on sightings for the five most commonly sighted species (bottlenose dolphin, harbor porpoise, minke whale, Risso’s dolphin, and common dolphin), at those sites with the longest time series, demonstrated seasonal, geographical and year-to-year differences in their local occurrence and relative abundance. Bottlenose dolphins are mainly present at observation sites located on the east coast of Scotland, being uncommon on the west coast, while harbor porpoise and minke whale are principally present at sites located on the west coast. The seasonality observed in cetacean occurrence is consistent with peak abundance in summer months described by previous studies in the area. Mean depth around the observation sites is the static variable that apparently has the greatest influence on species presence and number of sightings, except for Risso’s dolphin. All the species except bottlenose dolphin showed upward trends in occurrence and number of sightings over the period 2012–2018. Evidence of temporal autocorrelation was found between results from consecutive watches at the same site on the same day as well as between results from consecutive days at the same site. The power to detect declines in local abundance over a 6-year period depends on the underlying sighting rate of each cetacean species, the number of watches performed and the rate of decline. Simulations performed to determine the power to detect a decline suggest that the current intensity of observation effort in some observation sites, of about 2500 watches per year, may offer good prospects of detecting a 30% decline of the most frequently sighted species (95% of the time) over a 6-year period, although a more even distribution of observation effort in space and time is desirable. The data could potentially be used for monitoring and 6-yearly reporting of the status of cetacean populations.

Assessing the Role of Sampling Uncertainty When Predicting Behavioral Responses of Tagged Cetaceans Exposed to Naval Sonar

Concerns over cetacean mortality events coincident with maritime warfare exercises have motivated efforts to characterize the effects of anthropogenic noise on free-ranging whales and dolphins. By monitoring the movement, diving, and acoustic behaviors of individual whales before, during, and after sound exposure, behavioral response studies (BRSs) have supported significant progress in our understanding of the sensitivity of various cetacean species to high-powered naval sonar signals. However, differences in the designs and sampling capabilities of animal-borne tags typically used in BRS experiments prompt questions about the influence of data resolution in quantitative assessments of noise impacts. We conducted simulations to examine how uncertainty in the acoustic dose either measured on high-resolution multi-sensor biologging tags or modeled from position-transmitting satellite telemetry tags may affect predictions of behavioral responses in Cuvier’s beaked whales (Ziphius cavirostris) exposed to low- and mid-frequency active sonar. We considered an array of scenarios representative of real-world BRSs and used posterior estimates of dose-response functions obtained under an established Bayesian hierarchical modeling framework to explore the consequences of different tag choices for management decision-making. Our results indicate that (1) the zone of impact from a sonar source is under-estimated in most test conditions, (2) substantial reductions in the uncertainty surrounding dose-response relationships are possible at higher sample sizes, and (3) this largely holds true irrespective of tag choice under the scenarios considered, unless positional fixes from satellite tags are consistently poor. Strategic monitoring approaches that combine both archival biologging and satellite biotelemetry are essential for characterizing complex patterns of behavioral change in cetaceans exposed to increasing levels of acoustic disturbance. We suggest ways in which BRS protocols can be optimized to curtail the effects of uncertainty.