Mortality rate of the cladoceran Daphnia pulex as an indicator of water quality in the presence of three different types of antifouling paint
Stephanie Sardelis, Undergraduate Thesis, Queen’s University, (unpublished) 2013
Fouling, which is the growth of unwanted sessile organisms on the underside of boats, causes a number of issues for commercial fisheries, recreational boaters and environmentalists alike. This includes increase in fuel consumption, contamination of harvest and transportation of invasive species. One common strategy to prevent foulers from settling on boat hulls is to apply a toxic top coat of antifouling paint, which releases chemicals that prevent fouler settlement. However, this causes indiscriminate release of toxins into the surrounding waters, potentially poisoning marine organisms. I assessed what effects water-based, copolymer and biocide-free antifouling paints had on Daphnia pulex from three different lakes in a seven day chronic test. The paints I studied were Aquaguard Bottom Paint (Flexdel Corp.), Trilux II (Interlux) and EP-21 (e-Paint Company). Trilux II released the greatest amount of copper, Aquaguard released some copper but less than Trilux II, and EP-21 released zinc rather than copper. Daphnia pulex were collected from Elbow, Round and Solitaire lakes (Ontario). Individual Daphnia were placed in 15 mL test tubes of Lake Ontario water exposed to paint plates and I checked the survival of D. pulex every 24 hours to obtain a mortality rate. As well, the number of gravid individuals at the end of each trial was recorded. The results revealed that only the Trilux II copolymer and EP-21 biocide-free paints were significantly different from the controls, and that Aquaguard water-based paint was not. The results did not differ among Daphnia pulex from different lakes. A significant interaction was found between the treatment and lake for gravidity, where Elbow Lake had over all less reproduction in trials than Solitaire or Round lakes. Conclusively, my results indicated that paints with greater copper release increased mortality or non-target species, but the release of zinc is likely just as harmful.
Expressing Concern for the Least Concerned: Implementation of Management Units based on the analysis of genetic variation in Pacific pigeon guillemots (Cepphus columba) from the Aleutian Islands, Alaska to California
Stephanie Sardelis, Conservation Genetics, Queen’s University (unpublished) 2013
Evolutionary Significant Units (ESUs) are subpopulations of a species that are considered genetically or phenotypically distinct for conservation purposes, while Management Units (MUs) are not genetically isolated, but are demographically distinct. The purpose of our research is to determine the amount of genetic differentiation between clusters of pigeon guillemots (Cepphus columba) along the Pacific coast of North America to aid in their conservation. Tissue samples were collected from guillemots in Alaska to California, and analyzed for variation in nuclear DNA. Population genetics data analysis was conducted using the computational programs Arlequin and STRUCTURE. Results from these programs suggested that there are four distinct subpopulations of pigeon guillemots along the Pacific coast of North America: Alaska, British Columbia, Oregon and California. This variance could be a factor of isolation by distance, as well as local environmental differences influencing small groups of birds. Our results suggested that this Pacific avian population ideally should be delineated into four distinct ESUs. Dividing the population into four ESUs would allow local threats to be addressed directly and potentially for human-mediated migration to increase allelic variation and maintain gene flow. As well, areas that have populations in decline from oil spill-related incidents could be assigned unique conservation parameters. Finally, these results may instate reassessment of the population’s conservation status, looking more closely at each individual population rather than the entire range as a whole.
Investigating the effectiveness of toxic and non-toxic aluminum antifouling paints: settlement prevention of the invasive tunicate Botrylloides violaceus
Stephanie Sardelis, Directed Studies, Bamfield Marine Sciences Centre, (unpublished) 2012
Invasive species can be a major driver of species loss worldwide and can negatively affect fisheries. Preventing the settlement of Botrylloides violaceus, an invasive tunicate, on aquaculture gear is imperative because they can have a harmful influence on local environments and economies. A major vector of B. violaceus transportation is said gear. This study investigated the efficiency of toxic and non-toxic antifouling paints at preventing tunicate larvae settlement on aluminium. Tunicate larvae were given 48 hours to settle on a water-based ablative paint, a copolymer ablative paint, a biocide-free paint, or an aluminium plate with no paint. Based on a post-hoc chi-squared analysis, which compared the results to a homogenized distribution that assumes equal distribution across all trials, the copolymer paint had significantly less settlement than expected, the control had significantly more settlement than expected, and both the water-based and biocide-free paints did not deviate from the expected settlement. These results suggest that biocide-free paints could replace water-based toxic paints without reducing the paint’s capacity to prevent invasive species settlement. Based on this study, industry could use non-toxic antifouling paints on gear to reduce the spread of Botrylloides violaceus without chemically harming the harvest or the environment. Further research (conducted as my thesis at Queen’s University) should investigated how worthwhile this switch to non-toxic paints would be by testing the water quality associated with each of the paints.
Surfacing behaviour of harbour porpoises (Phocoena phocoena): A study conducted in the coastal waters of the Bay of Fundy
Stephanie Sardelis, Marine Mammals and Seabirds, Huntsman Marine Science Centre, (unpublished) 2012
A common inhabitant of the Bay of Fundy, the harbour porpoise (Phocoena phocoena), has been observed in small- to medium-sized groups. The objectives of this study were to determine the social behaviours associated with group formation, and to verify whether a porpoise’s duration of surfacing increased as their group size increases. Data were collected over 6 vessel-based surveys throughout the Passamaquoddy region, Bay of Fundy. Researchers tracked porpoise group size, number of respirations, duration of surface activity and other variables such the presence of boats or other species. The results revealed that the amount of breaths taken and duration of surfacing events were positively correlated to group size. The strongest correlation to harbour porpoise respiration behaviour was found when other marine mammals were present. These results suggest that harbour porpoise surfacing is not only related to respiration, but is also a type of social behaviour.
Investigating the efficiency of marine protected areas that restrict anthropogenic noise at mitigating declining fecundity of Southern resident Killer whales (Orcinus orca) by Letkovitch matrix modelling
Stephanie Sardelis, Marine Population Ecology and Dynamics, Bamfield Marine Sciences Centre, (unpublished) 2012
Building matrix models is a non-invasive method that allows for population dynamics and survival to be quantified, while estimating conservative population projections. A matrix model was constructed to project the population growth of the Southern resident Killer whales off the coast of British Colombia. The probabilities of survival, growth and reproduction were considered for each stage class in the life cycle of orcas: yearlings, juveniles, adults, and senescent adults. Fecundity parameters were applied to the current female population, which accounts for 50 out of 88 Southern individuals. Since orcas have such low adult mortality, this study assumed that the effects of anthropogenic noise most likely affected reproductive ability. If, hypothetically, reproduction was reduced by 50% under high noise stress, the population growth rate dropped from 2.5% per year, to 0.4%. An MPA may be able to sustain a population growth rate of 1.3% (considering it is impossible to block all noise). While anthropogenic noise can limit food acquisition, social interactions, and can reduce the stable age distribution, MPAs can potentially protect the population projection by maintaining a degree of reproduction.
Bycatch Reduction: Investigating mitigation methods to reduce negative interactions between fisheries and non-target marine species
Stephanie Sardelis, Fisheries Biology, Queen’s University, (unpublished) 2012
Bycatch is the incidental capture of non-target marine species in fishing gear. Unintentional capture generally results in increased immediate or delayed mortality rates; this is having a major impact on many marine populations, especially on K-Selective species (marine mammals, sea birds, elasmobranches). Fishing gear may be damaged during animals’ struggles to escape entrapment, and wasted handling time on non-target species results in economic loss.The first step to reducing bycatch is to implement tools to prevent further reduction in population via bycatch, like pingers or other Bycatch Reduction Devices (BDRs), and from there concentrate on ecosystem rehabilitation. The primary purpose of this article is to investigate the currently available mitigation tools. Although reduction efforts have been progressively implemented, the amount of international bycatch is predicted to far exceed current attempts. For bycatch reduction to be possible, political support, post-bycatch reducing device monitoring, and a substantial amount of further research are essential. As well, a multi-species approach must be adopted, since each type of fishing gear can affect a many organisms.
The Effects of Anthropogenic Noise Pollution on Cetaceans
Literature Review and Seminar
Stephanie Sardelis, Community and Ecosystem Ecology, Queen’s University, (unpublished) 2012
Cetaceans, of the order Cetacea, are marine mammals including whales, dolphins and porpoises. They use echolocation for orienteering, migration, mating and feeding, but this can often be interfered by under water noise generated by human activity. The ambient noise and pressure fluctuations that result are termed anthropogenic noise pollution. It can have a range of negative effects upon marine mammals, including habitat exclusion, signal masking or disruption, and physiological damage. The common causes of noise pollution investigated by this study are vessel traffic, acoustic harassment devices (AHDs), acoustic deterrent devices (ADDs), military sonar, pile driving, seismic surveys (airguns), and detonations. Noise effects are difficult to separate from other stimulus, and it is usually a combination of types that affect cetaceans, further increasing the difficulty of studying their individual effects. The ideal solution would be to cease noisy activities, but mitigation methods like bubble curtains, seasonal and spatial planning, and implementing political regulations are more practical.
Full papers (PDF) are available upon request.