by Hannah Calich, RJD Graduate Student and Intern

North Atlantic right whales (Eubalaena glacialis) are among the most endangered species of marine mammals in the world. Their Endangered status is largely due to the fact that they were heavily targeted by the whaling industry for over 300 years. During that time it is estimated that somewhere between 5,500 and 11,000 North Atlantic right whales were removed (Reilly et al., 2012). Currently, there are approximately 500 individuals left in the world (Pettis, 2012).

Despite the fact that these animals have been classified as Endangered since 1984 they are not recovering well (Reilly et al., 2012). Both biological and anthropogenic factors are influencing the North Atlantic right whale’s recovery. The primary biological factors hindering recovery are a lack of reproductively capable females, a slow growth rate, and low genetic diversity in the population. The primary anthropogenic factors include vessel strikes and entanglement in fishing gear. Efforts to mitigate the anthropogenic factors include moving shipping lanes out of migration routes and modifying gear to reduce entanglement.

Despite the fact that there has been intensive research on the North Atlantic right whale for over 30 years their mating grounds have remained a mystery, until recently. Timothy Cole et al. (2013) used observations from aerial surveys to monitor the distribution of North Atlantic right whales and help determine their mating grounds. Surveys were conducted along the eastern coast of the US and Canada between 2002 and 2008. When whales were sighted each whale was photographed to aid in identification. North Atlantic right whales are unique from other whale species in that each whale has a distinct pattern of callosities on its head that helps researchers identify individual animals (Figure 1).

The North Atlantic Right Whale Catalog is used to identify individual whales. The catalog consists of over 200,000 photographs and has been ongoing since 1935 (New England Aquarium, 2013). Each record indicates when and where a whale was last sighted, who saw it, and any additional information (e.g., the sex of the whale). Cole et al. (2013) identified fertile females based on their close association with a calf (Knowlton et al., 1994) and fertile males based on previous genetic analyses and paternity testing.

To determine the most likely location for mating Cole et al. (2013) examined where fertile males and females congregated during the mating season. Since the exact mating season for North Atlantic right whales has not been determined researchers made inferences based on observations of a close relative, the southern right whale (Eubalaena australis; Best, 1994). Additional cues about when North Atlantic right whales mate included observations of when and where their newborn calves are found, the predicted gestation period of the mother, and observations of courtship behaviors. When these observations were combined Cole et al. (2013) hypothesized that the mating season for the North Atlantic right whale falls between November and February.

Between November and February fertile male and female North Atlantic right whales form large aggregations in the central Gulf of Maine; suggesting that this is likely a mating ground for the species (Figure 2). In addition to finding a potential mating ground researchers also determined that the fertile females observed in this aggregation came from two separate subpopulations. This observation supports the idea that the entire North Atlantic right whale population may come to the central Gulf of Maine to mate.

Cole et al. (2013) also recorded high numbers of fertile individuals in Roseway Basin. However, the Roseway Basin aggregation occurred 1-2 months before the central Gulf of Maine aggregation. Since the mating period for North Atlantic right whales has not been confirmed it is possible that in comparison to southern right whales, North Atlantic right whales may have a longer gestation period. If that is the case, Roseway Basin may also be a mating ground for the North Atlantic right whale.

Food availability may be one of the most important factors in determining where mating will occur (Cole et al., 2013). Social factors such as feeding area preference may also play an important role. If food availability helps determine mating grounds, the mating location may change in response to changing food conditions. A longer time series of data is required to determine if the mating grounds change in response to changing prey availability.

The recovery of North Atlantic right whales largely depends on successful reproduction. Unfortunately, the current reproduction rate is very low. By working to determine when North Atlantic right whales mate and why they decide to mate where they do, researchers are taking important steps toward protecting this Endangered from Extinction.

REFERENCES

Best, P.B. (1994) Seasonality of reproduction and the length of gestation in southern right whales, Eubalaena australis. J Zool (Lond) 232:175−189

Cole, T.V.N., Hamilton, P., Henry, A.G., Duley, P., Pace III, R.M., White, B.N., Frasier, T. (2013) Evidence of a North Atlantic right whale Eubalaena glacialis mating ground.  Endang Species Res 21:55−64

Knowlton, A.R., Kraus, S.D., Kenney, R.D. (1994) Reproduction in North Atlantic right whales (Eubalaena glacialis). Can J Zool 72:1297−1305

New England Aquarium (2013) North Atlantic Right Whale Catalog. http://rwcatalog.neaq.org/Terms.aspx (accessed October 2013)

Pettis, H. (2012) North Atlantic Right Whale Consortium 2012 annual report card. Report to the North Atlantic Right Whale Consortium, November 2012. www.narwc.org/ pdf/2012_Report_Card.pdf (accessed October 2013)

Reilly, S.B., Bannister, J.L., Best, P.B., Brown, M., Brownell Jr., R.L., Butterworth, D.S., Clapham, P.J., Cooke, J., Donovan, G., Urbán, J. & Zerbini, A.N. (2012) Eubalaena glacialis. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.1. www.iucnredlist.org (accessed October 2013)

by Michelle Martinek, RJD Intern

The volcanic black sand beaches of Guatemala’s southeastern coast are usually a vision of natural beauty for residents and visitors, but lately they have been witness to a tragic event- the mass stranding of sea turtles. According to a statement released by the wildlife rescue and conservation association, ARCAS, eighty dead sea turtles have been recorded on the shores of La Barrona, Las Lisas, Chapeton, and Hawaii since the first week of July. Environmentalists suspect there may be a connection between nearby shrimping boats and the recent sea turtle strandings. Agriculture Ministry officials in Guatemala say the cause of the deaths will be investigated.

The majority of the dead animals were olive ridley sea turtles (Lepidochelys olivacea), Pacific green sea turtles (Chelonia mydas) and leatherbacks (Dermochelys coriacea). Olive ridley sea turtles are currently listed as Vulnerable by the IUCN and leatherback sea turtles are Critically Endangered. The entire coast of Guatemala, which borders the Pacific Ocean, has historically been an important nesting area for both olive ridley and leatherback sea turtles. Although not known to nest in Guatemala, east pacific green turtles forage in estuaries and mangrove waterways along the Pacific coast (Lutz and Musick).

Located between Mexico and El Salvador, the 250 miles of coastline in Guatemala is a small expanse of ideal habitat. It has rivers, mangroves, wetlands, lagoons, beaches, and attracts many sea turtles for feeding and nesting purposes. Residents are troubled by the recent deaths because the sea turtles are a valuable resource. Not only do they draw many tourists, but despite the endangered status of the turtles, their eggs are a source of food and income for locals. The success of sea turtle conservation in the area relies on 24 hatcheries, managed as part of a legal egg harvest. ARCAS is a non-profit NGO founded in 1989 which, among many other things, manages two of the 24 sea turtle hatcheries on the Pacific coast of Guatemala. Villagers are allowed to collect eggs laid on the beaches provided that 20 percent of each clutch is donated to a hatchery. This system was initiated in 1980 in an effort to conserve sea turtle populations. However, many of the hatcheries are underfunded and operating with limited scientific training. Short-staffing means that beach monitoring and research activities are rare events, making it hard to collect accurate data on the sea turtle strandings and status of the nestings.

The numerous dead sea turtles washing up on the beaches is suspected to be the result of the nearly unregulated shrimp harvesting industry operating in the nearby waters. Since sea turtles have lungs and must surface for air, they will drown if caught in the fine mesh nets used by shrimp boats. Although Guatemalan trawlers are required to use turtle excluder devices (TEDs), enforcement is difficult and fines are light.

In an interview for mongabay.com, Colum Muccio, ARCAS administrative director said, “I don’t think it’s a coincidence that when shrimp trawlers appear in the ocean that we begin having stranded turtles.”  ARCAS, along with other conservationists and researchers, are petitioning the government for action to combat the killing of the sea turtles. The lack of regulation in the egg harvesting and shrimping industry has the potential to severely hurt populations. The large number of sea turtle mortalities in the past six months can be used as an eye opener to the conservation community and world at large; something will need to change in order to save the lives of these already endangered animals.

REFERENCES

Avery, Lacey. “Eighty sea turtles wash up dead on the coast of Guatemala.” Guardian Environment Network 28 Aug 2013, Web. 1 Nov. 2013.

Lutz, Peter L., and John A. Musick. The Biology of Sea Turtles. CRC Press, 1997. 143-145. eBook.

http://www.arcasguatemala.com/

2013 was a great year for the University of Miami’s RJ Dunlap Marine Conservation Program, and we wanted to share some of the highlights with you!

1) We caught, measured, sampled and tagged 318 sharks, including 34 bull sharks, 23 lemon sharks,54 blacktip sharks, 35 tiger sharks, 20 great hammerheads, and even a great white! This included a successful expedition to tiger beach in the Bahamas. 19 tiger sharks, 3 scalloped hammerhead sharks, 7 great hammerheads, 8 bull sharks, and 1 blacktip shark were satellite tagged.

2) We took 1,584 people, of which well over 1,000 were high school students, out on the boat with us to learn about sharks and other marine science and conservation issues!

3) We published a paper about illegal shark fishing in the Galapagos.

4) We shared hundreds of marine science and conservation news stories on the RJD Facebook page, which now has over 3,000 fans! You should “like” us!

5) We published a paper about great white sharks scavenging on whales! You can see the video abstract here.

6) Using the RJ Dunlap twitter account (you should follow us), we held a twitter TeachIn about marine protected areas! This innovative teaching technique was profiled in Nature!

7) We published a paper about tiger shark feeding ecology and physiology! 

8 ) We co-hosted ScienceOnline Oceans, a conference focusing on how marine scientists can use internet tools for education and collaboration! Several RJD staff, including two undergraduate interns, moderated sessions!

9) We published a paper showing how social media can help scientists to write papers!

10) RJD students and staff spoke about sharks in over a dozen local schools, as well as to schools all over the country via Skype. We spoke with over 500 students around the country, from 1st grade through college!

11) We published a paper showing how social media can benefit conservation scientists!

12) We welcomed the largest new group of interns in RJD history!

13) RJD students and staff presented at several scientific conferences, including Benthic Ecology, the American Elasmobranch Society, the International Congress for Conservation Biology, and ScienceOnline Together!

Bonus: We partnered with Good World Games and the Guy Harvey Ocean Foundation to make Musingo, a music trivia app that helps the oceans!

2013 was a great year for the RJ Dunlap Marine Conservation Program, and we’re looking forward to an even better year in 2014! Thanks to all of our research collaborators, partners and donors! Thanks for reading, and Happy New Year!

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The RJ Dunlap Marine Conservation Program (RJD) is a joint initiative of the University of Miami’s Rosenstiel School of Marine & Atmospheric Science and Abess Center for Ecosystem Science and Policy. The mission of RJD is to advance ocean conservation and scientific literacy by conducting cutting edge scientific research and providing innovative and meaningful outreach opportunities for students through exhilarating hands-on research and virtual learning experiences in marine biology.

by Jake Jerome, RJD Intern

There is no debate that an oil spill is devastating to the marine environment. While many oppose the idea of drilling for oil in the ocean, the fact remains that it is currently happening and will continue into the future. Whether it be from direct drill sites in the ocean or oil tankers traveling the seas, we need to be prepared when there is an accident and oil leaks into the ocean. As our past actions have revealed, we still have a lot to learn about how to cope with an oil spill. Because no one agrees that one method is perfect, it is important to be well informed on some options and seek input so that an educated decision can be made.

Once an oil spill occurs, the first action that should immediately take place is stopping the pollution from the source (5). This can sometimes prove to be difficult as we learned from the Deepwater Horizon Oil Spill in April 2010. Once the oil is stopped, a variety of cleanup methods can be deployed to cope with the disaster. Each cleanup method has pros and cons. A review of possible options follows.

Booms/skimmers:

Booms vary in type but all have the same general design: a sub-surface skirt that prevents oil from escaping below the floating boom, a flotation device, and tension on the boom (2).  The purpose of booms are to contain surface oil within its boundaries so that collection of the oil can take place. Collection of the oil is often carried out by skimmers. Skimmers recover oil without altering its physical or chemical properties and can do so in a variety of ways, including suction and adhesion (5,2). While using booms and skimmers in conjunction is seen as the best option because the oil will be completely removed from the surface, it does face many challenges (2). One of the biggest limitations in the use of this method is surface conditions. Wind and waves encourage oil to carry out its natural tendency, to fragment and disperse itself in the water (2). Rough seas can prevent skimmers from functioning properly and can easily carry oil over the top of booms (2). Another downfall to this method is the ability to get the equipment operating and to the site in a timely manner. Even if the equipment is ready in a few hours, the oil will have had ample time to spread over several square kilometers, making the removal of the oil nearly impossible (2).

In situ burning:

In situ burning of surface oil involves a controlled ignition of spilled oil to essentially burn it off the surface of the water (5). In situ burning is often considered for Arctic or sub-Arctic environments because of their remoteness and sea ice formations that can constrict deployment of other methods (1). In situ burning has been shown to be less effective when used in ice corridors due to the high rate of melting sea ice (1). This reduces the thickness of oil, making it hard to ignite (1). In situ burning also presents environmental problems. Large clouds of black smoke rise from burning sites that not only pollute the air, but can impact communities both on the coast and far inland (2). In situ burning also leaves a residue that can coat coastlines or even worse, sink to cover benthic organisms (2).

Chemical dispersants:

Chemical dispersants are employed on oil spills for the purpose of accelerating the natural dispersion of oil in water (2). The dispersants release the tension between the oil and water and subsequently reduce the droplet size of the oil so it can be distributed in the water column (4). Once in small enough droplet sizes, the oil can be biodegraded by naturally occurring microorganisms (2). Chemical dispersants can quickly break up oil slicks and prevent large quantities of oil from covering coastlines and sensitive habitats. This method is considered to be a favorable option for coping with an oil spill. However, as in the other options, there are negative implications when using this method. There is great concern and debate that adding these chemical dispersants to the ocean is poisoning fish, corals, and other marine species. Goodbody-Gringley et al, found that the popular dispersant Corexit (R) 9500 significantly decreased the larval settlement and survival of two coral species. While this and other studies are telling, more research is needed to fully quantify the affect that dispersants have on the marine environment.

As you can see, choosing the correct method for cleaning up an oil spill can be difficult and is always situation dependent. There are many options that need to be considered before a decision is made, specifically determining the risks associated with each method. Although a quick response time is essential to eliminating a majority of the problems associated with an oil spill, more research needs to be done to help scientists fully understand the ramifications of each method. Overall effectiveness is vital, but unintended consequences must be weighed as well. For the present time these options appear to be the best available, but each should be weighed individually and in comparison to determine the most efficient and effect way to manage an environmental disaster such as an oil spill.

REFERENCES

Bellino, P.W., Rangwala, A.S., Flynn, M.R. “A study of in situ burning of crude oil in an ice channel” Proceedings of the Combustion Institute. Volume 34, Issue 2 (2013): 2539-2546

“Clean Up & Response.” ITOPF. N.p., 2013. Web. 28 Oct. 2013

Goodbody-Gringley, G., et al. “Toxicity Of Deepwater Horizon Source Oil And The Chemical Dispersant, Corexit® 9500, To Coral Larvae.” Plos ONE 8.1 (2013): 1-10

Kujawinski, E.B., Kido Soule, M.C., Valentine, D.L., Boysen, A.K., Longnecker, K., Redmond, M.C. “Fate of Dispersants Associated with the Deepwater Horizon Oil Spill” Environmental Science and Technology. 45. 4 (2011): 1298-1306

Ventikos, N.P., Vergetis, E., Psaraftis, H.N., Triantafyllou, G. “A High-Level Synthesis of Oil Spill Response Equipment and Countermeasures” Journal of Hazardous Materials. 107 (2004): 51-58

by Hanover Matz, RJD Intern

Constructed between 1998 and 2003, the Alqueva Dam lies in south-eastern Portugal. Situated in the Guadiana River valley, construction of the dam flooded an area of 250 km², creating the largest artificial lake in Europe. To determine the impact of this dam on the Eurasian otter (Lutra lutra), Pedroso et al. conducted a study across all phases of construction: pre-flooding, flooding, and post-flooding. The study focused on changes in otter distribution, otter diet and prey availability, and the availability of the main ecological requirements of otters, or what the otters need in a habitat to survive. Otters are apex predators in European fresh water food webs, and require connected river and stream habitats with specific bank structures to feed, reproduce, and thrive. Understanding the effects of human activities such as dam construction on river flow and otter ecology is important for conservation of both the otter species and its riverine habitat.

Surveys for the study were conducted across four main phases of the reservoir construction: pre-deforestation/flooding (2000), deforestation (2001), flooding (2002 and 2003) and post-flooding (2004 to 2006). This provided information not only on the effects of reservoir construction on otters throughout all parts of the process, but also long-term monitoring after the completion of the dam. The survey area of the reservoir and surrounding region was organized into a grid consisting of 25 km² cells. In each cell, the survey teams searched for and recorded signs of otters present in the area. 39 1 km² survey areas were then randomly selected within the flooded area and assessed as well. To determine changes in otter diet and prey availability, samples of otter spraints (feces) were searched for prey items and identified. Survey teams also collected prey animals in the local streams. Finally, the availability of otter ecological requirements was determined in each 1 km² cell based on five qualifications: availability of prey and feeding areas, availability of resting sites, suitability for breeding, availability of corridors for movement, and accessibility to fresh water.

Over the course of the construction, the study found that the percentage of the area occupied by otters on the 25 km² scale did not change significantly. The distribution of otters shifted throughout the region during the flooding phase, and on the 1 km² scale there was a decrease in otters during the deforestation and flooding phases, with some recovery after completion of the project. Prey sampling showed that construction of the reservoir lead to a decrease in the numbers of different species of fish and crustaceans eaten by the otters, as well as a shift towards consumption of non-native species over native prey animals. Assessment of ecological availability showed that all qualifications decreased with the construction of the dam, except for accessibility to fresh water. This increased due to the establishment of the permanent reservoir rather than streams which may disappear during the dry season.

These results indicate that although creation of the Alqueva Reservoir may not have seriously impacted the numbers of otters in the region, it has caused a shift in how the otters feed and what ecological requirements are available to them. The shift to a consumption of less diversified prey animals and more non-native species indicates a change in the community of the fresh water habitats. Now that the rivers and streams have been replaced with a standing reservoir, better adapted non-native species of fish and crustaceans such as Procambarus clarkia, a crayfish from the U.S., may be outcompeting native species. Also, a shift in otter diet to smaller, non-native fish means the otters must eat more fish than before to maintain the same amount of biomass. Construction of the reservoir has also changed the habitat available to the otters. Flooding of the banks of rivers and streams has removed the holes and recesses the otters use for breeding, leaving only unsuitable rocky outcrops on the reservoir edges. Removal of shallow river banks also eliminates prime prey habitat and hunting grounds for the otter.

While the Alqueva Reservoir may still be able to support a stable population of Eurasian otters, it is possible that the same alterations to habitat in other areas may harm less dense populations. As stated by the authors, “[…] dams do not offer equal opportunities for otter populations compared with a network of rivers and streams.” These opportunities include access to prey, breeding sites, and corridors for movement from one habitat to another.  This study shows the importance of conserving the appropriate habitat structures and qualities necessary for the otters to survive. It also has wide reaching applications to conservation across the world. Monitoring apex predators, whether they are otters in European rivers, lions on the African Serengeti, or sharks in the world’s oceans is an effective way to gauge the health of an ecosystem. If the top predators in a food web have drastically changed in numbers or behavior, it is likely that an ecological disturbance has occurred somewhere down the chain. To better assess the impact of human activities on the environment, studies such as this one are necessary for conservation and protection.

REFERENCE

Pedroso, Nuno M., Tiago A. Marques, and Margarida Santos‐Reis. “The response of otters to environmental changes imposed by the construction of large dams.” Aquatic Conservation: Marine and Freshwater Ecosystems (2013).