April 7 – Comprehensive, decadal data on coral bleaching and increased sea surface temperatures

Coral bleaching (in which corals lose their color) happens due to the thermal stress that affects the symbiotic relationship between corals and their algae. Hughes et al., 2017 describe (through both aerial and ground truthing evidence) that the Great Barrier reef has gone through mass bleaching events in 1998, 2002 and 2016. In this most recent event (2016), the effects on the reef were much worse, as seas surface temperatures were higher, more reefs were bleached, and the reefs affected were bleached at a higher intensity. Northern reefs on the eastern coast of Australia saw the most detrimental effects. Unfortunately, water quality and fishing pressure do not have a large effect in contrast to the overall bleaching. However, it remains important to continue to promote the recovery of reefs through local management and water quality, especially to a reef as economically and ecologically important as the Great Barrier reef.  Ultimately, we need urgent and rapid action to reduce global warming to support the reef through the bleaching resistance. – Annie

Image via: By Samuel Chow (originally posted to Flickr as Bleached Coral)

Citation – Hughes, T. P., Kerry, J. T., Álvarez-Noriega, M., Álvarez-Romero, J. G., Anderson, K. D., Baird, A. H., … & Bridge, T. C. (2017). Global warming and recurrent mass bleaching of corals. Nature, 543(7645), 373-377.

AuthorsTerry P. Hughes, James T. Kerry, Mariana Álvarez-Noriega, Jorge G. Álvarez-Romero, Kristen D. Anderson, Andrew H. Baird, Russell C. Babcock, Maria Beger, David R. Bellwood, Ray Berkelmans, Tom C. Bridge, Ian R. Butler, Maria Byrne, Neal E. Cantin, Steve Comeau, Sean R. Connolly, Graeme S. Cumming, Steven J. Dalton, Guillermo Diaz-Pulido, C. Mark Eakin, Will F. Figuera, James P. Gilmour, Hugo B. Harrison, Scott F. Heron, Andrew S. Hoey, Jean-Paul A. Hobbs, Mia O. Hoogenboom, Emma V. Kennedy, Chao-yang Kuo, Janice M. Lough, Ryan J. Lowe, Gang Liu, Malcolm T. McCulloch, Hamish A. Malcolm, Michael J. McWilliam, John M. Pandolfi, Rachel J. Pears, Morgan S. Pratchett, Verena Schoepf, Tristan Simpson, William J. Skirving, Brigitte Sommer, Gergely Torda, David R. Wachenfeld, Bette L. Willis & Shaun K. Wilson.

Presenter – Annie Tamalavage

March 24 – Cumulative impacts of noise, light, and chemical pollution on animal perception

Numerous studies and papers exist on the effects of anthropogenic pollution (acoustic, light, chemical, etc.) on ecosystems and the organisms inhabiting these areas.  However, most of these same studies only examine stimuli and perception from a unimodal perspective, ignoring the possible co-occurrence of multiple types of stimuli, or the influence of pollution on more than one sensory receptor and system.  Reception and processing of external stimuli is a complex pathway involving interplay between perception and cognition, leading to behavioral or endocrinal responses, or a combination of both.  This can lead to difficulties in identifying exact causes of specific behaviors, but does not diminish the necessity for collection of data on the subject.  Taking a multimodal research approach can help to better understand human ecological impacts and lead us to better conservation practices. – Nathan

Image via: By Lamiot

Authors – Halfwerk, W., & Slabbekoorn, H.

Citation – Halfwerk, W., & Slabbekoorn, H. (2015). Pollution going multimodal: the complex impact of the human-altered sensory environment on animal perception and performance. Biology letters, 11(4), 20141051.

Presenter – Nathan Reed

March 10 – Trade offs between biodiversity and Hydropower

This study assesses the impacts of Mekong River tributary dams on biodiversity and biomass of fish in the Mekong River basin. Current policy requires approval from all countries sharing the Mekong River Basin before dams can be built on the main river, but there is little regulation of, or information on, dams built on tributaries. This is potentially problematic because tributary dams built in one country may greatly impact fish biomass in another country, and several countries along the Mekong River have populations that rely on subsistence fisheries.

The authors used ecological models regarding fish migration in the wet and dry seasons to estimate the impact of tributary dams and compared these results with the estimated hydropower to be produced by each dam project. They found that multiple dams on the main river would generate more power while having less effect on fish than any combination of tributary dams. Assuming that tributary dams would still be pursued, the authors also generated a selection tool for selecting the least destructive combination of tributary dams for the amount of power generation required. – Janelle

Image via: Peter Rood

Authors- Ziv, G, E Baran, S Nam, I Rodriguez-Iturbe, and SA Levin.

Citation – Ziv, G, E Baran, S Nam, I Rodriguez-Iturbe, and SA Levin. 2012. Trading-off fish biodiversity, food security, and hydropower in the Mekong River Basin. PNAS 109(15): 5609-5614.

Presenter – Janelle Espinoza

March 3 – The importance of bait worms as a fishery

What is one of the most frequently used baits when fishing? Worms! However, do we actually consider our impact on their populations when we go digging for them? This week we discussed this topic and the fact that there is growing concern about management of marine bait worm fisheries. Watson and colleagues pulled information from the literature, conducted surveys, placed cameras overlooking worm collection sites, and ran an experiment to assess how long Nereis virens could be kept alive under varying conditions. They estimated that 121,000 metric tons of polychaetes are landed every year across the globe. That is a substantial amount of worms. Additionally, they found that much of the digging activity occurs in areas that have been dug. Their experiments to assess the longevity of Nereis virens resulted in the finding that with refrigeration and a simple storage method the worms could be kept alive for two weeks. This was discussed as a potential management method, to encourage anglers to get the most out of their worms. One point that we discussed a lot was the potential impact of digging on the bird communities. Check out this video https://www.youtube.com/watch?v=nwmpk3Ie9xI for an example of blood worm (Glycera) digging in Maine. You can imagine how this reworking of the sediment could disturb bird foraging activities. – Justin

Image via: Wayne National Forest

Article – Bait worms: a valuable and important fishery with implications for fisheries and conservation management.

Citation – Watson, G. J., Murray, J. M., Schaefer, M., & Bonner, A. (2016). Bait worms: a valuable and important fishery with implications for fisheries and conservation management. Fish and Fisheries.

Presenter – Justin Hilliard

Feb. 24 – Anthropogenic factors and impacts on coastal, tropical waterbirds.

Looking at the various environmental and anthropogenic factors associated with waterbirds in tropical coastal lagoons, this paper observed the abundances of six different guilds of waterbirds. Each guild was classified based on size and foraging strategy, in relation to variables such as lagoon size, water depth, livestock grazing pressure, and distance from human settlements among others. The group seemed to be in agreement that it was an appropriate decision for the researchers to use guild when investigating these effects. Overall, water depth had the greatest correlation with abundances of multiple bird guilds. One interesting part of the discussion was when the group talked about how Principal Components Analysis was applied to this study. This is a type of analysis that some members of the group were familiar with, and others were not. It was a good learning experience when those who have used this tool before were able to explain to others in greater detail how this type of analysis works. Lastly, this paper lists some specific management strategies that could be implemented based on their findings. – Rachael

Image via: Rodrigo Mariaca

Article – Environmental and anthropogenic factors structuring waterbird habitats of tropical coastal lagoons: implications for management.

Citation – Tavares, D. C., Guadagnin, D. L., de Moura, J. F., Siciliano, S., & Merico, A. (2015). Environmental and anthropogenic factors structuring waterbird habitats of tropical coastal lagoons: implications for management. Biological Conservation, 186, 12-21.

Presenter – Rachael Glazner

Feb. 17 – Plastic pellets and the spread of PCBs

In this paper, the authors were looking at the ability of plastic pellets, made of resin, to absorb, transport, and transmittance PCBs in the environment. The authors investigated how the type of resin may influence PCB concentrations (polypropylene vs. polyethylene) and found that PE pellets contain higher concentrations of toxins than PP. The color of the pellet was also investigated as many animals tend to forage based on a color preference, as such pellets were ranked by various states of discoloration and/or environmental fouling (e.g. algae). It was found that the discolored, fouled pellets contain more toxins, which could have detrimental effects to birds and fish that preferentially feed on yellowed particles that could mimic food sources. A spatial aspect was evaluated to help understand how distribution over larger distances may impact the spread of PCBs at various sites, and any potential regional or local variation. Overall, regional variation showed that areas closer to manufacturing plants where PCBs are/have been released, have a higher concentration, while sites further away have lower concentrations. Locally, sites can have large variations from one pellet to another. Having set up the baseline for distribution and potential risk of PCB uptake, the authors suggested future studies examine the ingestion rate of these pellets into the food web. – Shawna

Image via: By Wusel007

Article – Concentration of polychlorinated biphenyls (PCBs) in beached resin pellets: variability among individual particles and regional differences.

Citation – Endo, S., Takizawa, R., Okuda, K., Takada, H., Chiba, K., Kanehiro, H., … & Date, T. (2005). Concentration of polychlorinated biphenyls (PCBs) in beached resin pellets: variability among individual particles and regional differences. Marine Pollution Bulletin, 50(10), 1103-1114.

Presenter – Thompson Ware

Feb. 10 -Threats to Artic marine mammals and necessary conservation

With the near inevitability of global climate change drastically altering the arctic ecosystem, it is important to consider the potential threats that arctic species will soon face.  This week in Journal Club, we discussed an article by Huntington which assessed 6 areas of human influence that will likely threaten marine mammals over the next several decades.  These factors of concern include climate change, environmental contaminants, offshore oil and gas activities, shipping, hunting, and commercial fisheries.  Huntington examined the interactions between these factors, their nature and magnitude, current understanding, and conservation potential.  Of the 6 factors, climate change, industrial development, and commercial fishing seem to harbor the greatest potential threat to arctic marine mammals, either because of the magnitude of the threat or because of our general lack of knowledge of how these factors will develop in the near future.  Huntington also mentions that the interactions and synergistic effects will likely pose a greater threat to arctic species than any one of these factors alone. – Nick

Image via: By Hannes Grobe 21:16, 12 November 2006 (UTC), Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany.

Article – A preliminary assessment of threats to arctic marine mammals and their conservation in the coming decades.

Citation – Huntington, H. P. (2009). A preliminary assessment of threats to arctic marine mammals and their conservation in the coming decades. Marine Policy, 33(1), 77-82.

Presenter – Nick Zellmer