Category: Uncategorized

Toxic dinoflagellates: introduction of potentially harmful dinoflagellates due to ballast water in Eastern Canada

Jacqueline Modler \ Oceans First \ Issue 4, 2017, pgs 28-34. Download PDF

Abstract

Ballast water frequently introduces potentially harmful, non-indigenous dinoflagellates into marine ecosystems, either through water or within ballast sediments. Foreign dinoflagellates contribute to the development of harmful algal blooms, and affect aquaculture and human health due to paralytic shellfish poison (PSP). Eastern Canadian marine ecosystems are becoming increasingly vulnerable due to rising water temperatures, enabling tropical dinoflagellates to survive in an environment that was previously too cold. Ships participating in a coastal ballast exchange have the highest probability of transporting harmful, non-indigenous dinoflagellates. This paper aims to prove that additional methods of control are needed to limit the number of harmful dinoflagellates transported by ballast water. Ballast water exchange, made law in 2006, is an insufficient method to control the introduction of foreign taxa, and when done in coastal waters, could instead increase the number of toxic dinoflagellates brought into marine ecosystems. The implementation of an external Canadian management body is proposed to regulate ballast water exchange and tighten ballast water requirements. Studies in Eastern Canada will be used to examine the magnitude of harmful, non-indigenous dinoflagellates introduced in Eastern Canada. As well, national and international studies will be brought together to examine potential effect of non-indigenous dinoflagellates.

Altered Behaviors of Reef Fish in Bleached Coral Environments and their Imposed Impacts on Reef Fish Populations

Aaron Clausen \ Oceans First, Issue 4, 2017, pgs. 9-15.  Download PDF

Abstract

For the first time in history atmospheric carbon levels have reached and exceeded 400ppt. This exponential increase in atmospheric carbon has lead to the major changes in the climate that has significantly impacted coral reef health across the wold. Global temperature rise is increasing ocean temperatures, and acidity. These stressors have lead to large scale bleaching of corals. The degradation of these corals has been linked to multiple noteworthy changes in the behaviours of reef fish inhabiting bleached corals. Reef fish are not responding to predator cues as they would in pristine reefs, as the cues related to the presence of a predator are not being detected by reef fish. Despite the loss of camouflage resulting from bleached white coral backgrounds reef fish have been displaying more aggressive behaviour, resulting in increased vulnerability to predators. The settlement preferences of reef fish have been altered, resulting in migration from their bleached environments to healthier reefs. These changes are lowering prey fish populations and influencing change in reef population dynamics. This review will synthesize key findings involving altered behavior of reef fish, and the impacts of these changes on reef populations.

Fibropapilloma in Hawaiian Green Sea Turtles: The Path to Extinction

Natalie Colbourne \ Oceans First, Issue 4, 2017, pgs. 16-22.  Download PDF

Abstract

Fibropapilloma (FP) tumors have become more severe in Hawaiian green sea turtles since they were first found in 1928. The nitrogen footprint found in foraging grounds, in which sea turtles live and feed, is the main cause of FP in green sea turtles. Nitrogen is converted into arginine, an amino acid that causes tumor formation by algae, that sea turtles consume. Many studies have been conducted on the disease and it has been concluded that the severity of the tumors is higher in turtles with larger carapace (shell length). As well, some studies have shown that where there is nitrogen waste, there is also an increased disease rate, and that these locations are foraging grounds. It was also proven that these locations contain macroalgae with arginine, further proving that there is a direct relationship between where these algae were found and where sea turtles with FP live and feed. Green sea turtles are endangered and it is crucial that we understand FP completely in order to eliminate the disease. This review will explain how nitrogen waste causes severe Fibropapilloma tumors in Hawaiian green sea turtles.

Potential use of Hydrophobic Aerogels in future oil spill clean-ups

Hinna Hafeez \ Oceans First, Issue 4, 2017, pgs. 23-27.  Download PDF

Abstract

For thirty years, oil spill clean up methods did not change until the Deepwater Horizon Spill, the worst marine oil spill in history, occurred in 2010. This notion has motivated scientific advancement of more efficient methods than those used in the Deepwater Horizon Spill. To date, the most notable oil spill clean up method that was used is the dispersant Corexit 9500. This chemical has been found to negatively affect mammalian cells including inducing oxidative stress and premature cell death. It was also found that the oil dispersed by Corexit 9500 remained in the water and continued to affect marine life one year after the spill. Among the proposals for new clean up methods, hydrophobic, low density solids called aerogels are a serious contender for large scale clean ups in the future. Hydrophobic aerogels act as sponges to absorb oil and not water and can remove several types of oils including dispersed and emulsified oil. The oil can be later removed from the gel to be used commercially. However, aerogels are costly and time-consuming to make and have not yet been tested on a large-scale basis. Next steps should include testing aerogels in the ocean and potentially using them to remove remaining dispersed oils caused by the use of Corexit 9500.

The Role of Iron Fertilization in the Fight Against Climate Change

Bronwen Rowe \ Oceans First, Issue 4, 2017, pgs. 35-42.  Download PDF

Abstract

The input of continental dust plays an important role in biogeochemical cycles in the ocean. This paper brings together information from iron fertilization experiments as well as natural event observations (such as the natural input of continental dust into the ocean, or volcanoes) to highlight how understanding the ramifications of continental dust input into the ocean can be applied to combat climate change. Scientists use the radioactive isotope Thorium-232 as a proxy to determine the input of continental dust into the ocean, and volcanic events are studied to observe the results of a large iron input. The “Iron Fertilization Hypothesis” is proposed as a carbon sink to remove excess CO2 from the atmosphere. It is done by seeding the ocean with iron, a nutrient that limits phytoplankton growth in high nutrient low chlorophyll (HNLC) areas, such as the Southern Ocean. After reviewing the pros and cons of iron fertilization, it was determined that iron fertilization should be considered to combat climate change, but it needs to undergo more testing and research. Areas for further study include toxic blooms, the amount of biomass that is reaches the seafloor (via sediment cores) and if ocean iron fertilization is legal or considered ocean dumping.

Phytoplankton Climate Regulation in Positive and Negative Feedback Systems: The CLAW and anti-CLAW hypotheses

Adam Stoer \ Oceans First, Issue 4, 2017, pgs. 43-52.  Download PDF

Abstract

The global climate crisis is bigger now than it has ever been before, pushing for much-needed research on the consequences of climate change. In 1987, Charlson, Lovelock, Andreae, and Warren proposed the CLAW hypothesis which stated that phytoplankton contribute to the production of a significant amount of cloud condensation nuclei (CCN) which in turn creates a negative feedback loop after there is an initial temperature rise. Many years later, in 2006, Lovelock proposed the anti-CLAW hypothesis, which argues that a similar process occurs except that it works as a positive feedback system. Both hypotheses have created much controversy about the effects phytoplankton has on climate and climate regulation. Research has shown that different types of phytoplankton tend to have higher growth rates within a temperature range. Coccolithophores are known for their contribution of DMSP, a compound that forms to make CCN as well as their carbon sequestration abilities. This type of phytoplankton typically function at a thermal niche where nutrient stratification is not strongly limiting, making them act like a buffer against further temperature rises in terms of the CLAW hypothesis. Based on the physiological capabilities of phytoplankton within their environment, both the CLAW and anti-CLAW mechanisms correlate strongly with coccolithophorid algae.

Electrolysis: Is it enough to save the coral?

Taylor Watts \ Oceans First, Issue 4, 2017, pgs. 53-60.  Download PDF

Abstract

Corals all over the world are diminishing quickly due to ocean acidification and from human causes. Future predictions state that coral calcification will decline by 78% by 2100 due to greenhouse gas emissions (Rinkevich. 2015); if the corals disappear our oceans will suffer. Once corals die or become damaged, healing and the rebuilding of their calcium carbonate structure takes far too long; this means corals are diminishing far faster than they are being replenished. A new scientific process called electrolysis has since been discovered that may be the only chance for corals to gain any ground in rebuilding themselves. Electrolysis is the process of using electric current to create environments with high concentrations of calcium and carbonate ions in order for natural calcification to occur. However, electrolysis is not a well-known practice, nor is it heavily experimented. This paper discusses the process of electrolysis and the benefits of such a practice. The main goal of this paper is to prove that the process of electrolysis to rehabilitate corals should be used on a global scale.