JELLYFISH AND THEIR PREDATORS

Jellyfish are amazing animals. Almost entirely made of water, without a brain or central nervous system, they manage to get around the oceans very successfully.

One of the common species in the eastern North Pacific is the sea nettle, Chrysaora fuscescens. This species is among the better known Pacific coast jellyfish because it can be kept in aquaria. It can become superabundant in our waters, presumably when the zooplankton on which it feeds are similarly abundant, but it also may be because of the vagaries of ocean currents. Jellyfish generally swim upcurrent so they encounter a regular supply of the tiny animals on which they feed.

Not very many animals feed on jellyfish because of a combination of their fairly effective antipredator adaptions and their very low nutrient content. Two of these that do so are actually specialists, large animals that roam slowly around the world’s oceans and eventually run into single or even concentrations of jellyfish.

The Ocean Sunfish (Mola mola) is the more common of these two species. This is the largest and best-known species of its family and in fact the heaviest bony fish in the world, with an average weight of 1,000 kilograms. It looks about like a head with fins, swimming with a sculling motion of the big dorsal and anal fins. A long fin waving at the water surface is usually a good indication of one of these two-meter monsters.

Ocean sunfish are usually found floating at the surface on their side, perhaps taking advantage of the warmest surface water to more effectively digest the great amount of jellyfish they have to eat to gain adequate nutrition. We see them when they are at the surface, but in fact they spend much of their time well below the surface and perhaps come up just to warm up!

Ocean Sunfish are known to lay the most eggs of any animal in the world, up to 300 million eggs at one time. The larvae look nothing like the adults but are more like the larvae of other members of their order, including puffers and porcupine fish. It is rare to sight groups of juveniles, but five such groups were seen off Grays Harbor in September 2013; presumably like other fish, they school for protection from predators, among them sharks and sea lions.

The other main medusivore, as a jellyfish-eater should be called, is the Leatherback Turtle (Dermochelys coriacea). This is also huge for its group, the largest living turtle at an average weight of 400 kilograms. The largest ever recorded had a carapace length of over 2.2 meters. These animals are very different from the sunfish in that they have to go to shore to nest, and the ones in our waters are migrants from, amazingly, the Southwest Pacific.

Of all the sea turtles, this is the one most capable of living in cold waters, even north to the Gulf of Alaska. They generate metabolic heat by swimming, and they are insulated by fat as well as warmed by counter-current heat exchange in their blood vessels. Although “cold-blooded” like other reptiles, their body temperature has been recorded as up to 18° C. warmer than the water in which they swam.

Northern Fulmars (Fulmarus glacialis) also eat large jellyfish, among the few birds that do so. The cnidarians because of their watery nature are poorly represented in stomach contents, but observers have seen them picking at jellies. They appear to go after the gonads, which are doubtless more nutritious and oil-rich than the rest of the animal.

And all these animals eat their jelly without peanut butter!

Dennis Paulson

Microplastic ingestion by seabirds: ongoing research at the Slater Museum

Plastic from a Northern Fulmar stomach 

Research on ingestion of microplastics by seabirds continues at the Slater Museum.  With the help of Shep Thorpe, VMD, we have examined additional Northern Fulmar stomachs from 2012 from the WA and OR coast.  These were recovered by Wildlife Center of the North Coast (WCNC), Sharnelle Fee director.  There was an additional bird from Ocean Shores, WA provided by Sheila McCartan, Nisqually NWR.  The Ocean Shores bird was remarkable in having 6.0 gm of plastic in the proventriculus and 1.04 gm in the ventriculus (pictured).  Some pieces were the size of guitar picks.  There was one nurdle (labeled) which is a premanufactured plastic pellet.  Typically fulmars have less than 1 gm.  The Ocean Shores bird probably had enough plastic to incapacitate it leading to its demise. 

Research continues to rely on collection of specimens by Sharnelle Fee, Wildlife Center of the North Coast and Shep Thorpe, DVM, for dissection and separation of stomach contents.  Shep expanded discovery to the intestines where he has discovered small particles of plastic, parasites and clues to causes of mortality.   

Professor Peter Hodum in Biology is directing the research with students Alicia Terepocki, Alan Brush and Olivia Feinstein.  All are presenting posters based on their research over the past year at the Pacific Seabird Conference in Portland this month.

Abstracts from the Pacific Seabird Group 40^th Annual Meeting 20-24 February 2013 Portland

USE OF A DIVING PROCELLARIIFORM, THE SOOTY SHEARWATER, TO EXPAND A MARINE PLASTIC BIODINDICATOR NETWORK

Alexander Brush, Gary Shugart and Peter Hodum, Biology Dept & Slater Museum., University of Puget Sound, 1500 N. Warner, Tacoma, WA 98416 USA, ABrush@pugetsound.edu

There is growing recognition that plastic pollution in our oceans has reached a critical level and must be addressed. Seabirds, especially procellariiforms, have proven to be a useful bioindicator of marine plastic debris through the monitoring of their ingestion habits. To date, most efforts in documenting procellariiform ingestion of plastic have focused on primarily surface-foraging species. There is reason to suspect, however, that pursuit diving species may not reflect the same plastic ingestion patterns. In this study, we examined the stomach contents of Sooty Shearwaters (Puffinus griseus), a species that uses both surface seizing and pursuit diving to forage. We collected samples from 26 birds from the northern Oregon/southern Washington region to quantify the frequency of occurrence, abundance, color and size of plastics in the diet. Plastic was found in 69% (18 out of 26) of specimens, which is lower than incidences of plastics in Fulmar stomachs. The abundance, color and size of plastics found in the Shearwaters will also be presented. Due to the differing feeding habits in Shearwaters versus Fulmars, it was expected that plastic categorizations would produce different results in the two species for amounts and types of plastics found. If our hope is to create a comprehensive network of seabird bioindicators of plastic debris then our knowledge base must be expanded to species that reflect a wide variety of foraging guilds, as they are likely to provide unique insights into the marine plastic issue.

NOTHERN FULMARS (FULMARIS GLACIALIS) AS BIOINDICATORS OF ENDOCRINE DISRUPTING PLASTICIZERS IN THE MARINE SURFACE ENVIRONMENT

Olivia Feinstein*¹, Erica Donnelly², Hannah Nevins² and Peter Hodum^1,2, ¹Biology Dept., University of Puget Sound, Tacoma, WA, 98416 USA, ofeinstein@pugetsounde.edu 2Oikonos Ecosystem Knowledge, Benicia, CA

Many phthalates used to synthesize plastics have been identified as endocrine disrupting chemicals (EDCs), with studies showing dramatic deleterious effects on a variety of species as a result of exposure to growing numbers of EDCs in the environment. The Northern Fulmar (Fulmarus glacialis) is an opportunistic seabird which inadvertently consumes plastics as it forages. Previous studies of Fulmars suggest that plastics are leaching EDCs into the bird’s systems. We determined the percentage of plastics ingested by fulmars that contain EDCs. A collaboration with the Long Marine Research Lab allowed for geographic comparisons of EDC concentration intensities along the West Coast. The percentage of plastics in the diet of fulmars that contained plasticizers was below 3% in all tested regions. Plastic proportions in Alaska differed significantly from those in California and Washington. Our analyses confirmed that fulmars are effective bio-indicators of plastics in surface marine environments and that the surface waters in tested regions are not highly contaminated by plastics containing EDCs. EDC-containing plastics typically displayed negative buoyancy and sank in seawater and may be accumulating in benthic regions. The impacts of plastic ingestion may be a more significant source of contaminant uptake by seabird species than previously assumed. Additionally, there are physical consequences to species; plastics take up volume in the stomach reducing digestive capacity which blocks nutrient absorption.

PLASTICS IN THE PACIFIC: REGIONAL COMPARISONS OF MARINE PLASTIC INGESTION BY NORTHERN FULMARS

Alicia Terepocki*¹, Erica Donnelly², Hannah Nevins², Gary Shugart1 and Peter Hodum^1,2, ¹Biology Dept & Slater Museum., University of Puget Sound, Tacoma, WA, 98416 USA, aterepocki@pugetsounde.edu 2Oikonos Ecosystem Knowledge, Benicia, CA

Plastic pollution is increasingly recognized as an escalating threat to marine ecosystems. In the face of this developing issue, monitoring ocean-wide levels of pollution has become crucial. Successful monitoring programs utilizing Northern Fulmars (Fulmarus glacialis) as bioindicators of marine plastic pollution have been instituted in northern Europe and central California. As generalist and surface feeders, fulmars are an ideal indicator due to their susceptibility to ingesting plastic debris. In this study, we examined fulmars from northern Oregon and southern Washington (n=89) to determine the frequency of occurrence, abundance, size and color of plastic ingested and make inferences about the state of marine plastic pollution in the Pacific Northwest and feeding habits of fulmars. We compared these findings with those of birds from Alaska (n=46) and California (n=44) to obtain information on regional differences in plastic pollution in the northeastern Pacific. Results suggest marine plastic densities vary regionally, in all regions plastic ingestion was prevalent.

PSG’s 40^th Annual Meeting:

February 20-24, 2013 at the Portland Hilton

*

Microplastics in Northern Fulmars as an indicator of marine plastic debris in the North Pacific

(Results in press as of 8 Jul 2012 at http://www.sciencedirect.com/science/article/pii/S0025326X12001828, pdf available upon request.)

Marine plastic debris is an increasing problem in ocean ecosystems. Plastic degrades slowly on land, but in the ocean it persists even longer – if left to its own devices, potentially for hundreds or thousands of years. Also, because plastic is light, it floats or is suspended in the water column and can be carried long distances from its origin by ocean currents. To see just how big of a problem this has become, you need only look a little to the west of our own coastline at the “Great Pacific Garbage Patch” – a mass of trash larger than Texas accumulating at the center of a current system called the Northern Pacific Gyre.

Plastic in marine ecosystems can be extremely harmful to wildlife. Animals can not only become entangled in the debris, but they can also eat the tiny “microplastic” particles that are the result of plastic trash being broken apart in the ocean. Seabirds in particular are known to suffer a great deal from plastic ingestion, which can have serious negative consequences to their health as plastic can accumulate in the gut, reducing stomach capacity, obstructing digestion and causing starvation and reduced growth.

The only good side to this situation is that we can use some seabird species as indicators of marine plastic debris in the environment. Not all seabirds eat or accumulate a lot of plastic – some dive for their food and manage to bypass the surface realms of floating plastic. Some are not so lucky. Procellariids, or “tube-noses” including birds such as albatrosses, petrels, and fulmars, are some of the most extreme accumulators of plastic. This is primarily because they are surface-feeders and are more likely to swallow floating microplastics – presumably as a result of confusing them with food.

Northern Fulmars (Fulmarus glacialis) in particular have been accepted as the best indicator species for marine plastic debris in the northern hemisphere. This is mostly due to their extremely wide range and distribution – they can be found in the North Pacific, North Atlantic, and the High and Low Arctic. They can therefore be used as an international standard indicator of marine plastics. Monitoring projects focusing on microplastics in Fulmars in the Arctic and Atlantic are fairly wide-spread and well-established. However, data for the North Pacific is lacking and outdated since the 1990s. This fall, I made a first attempt at rectifying this lack of monitoring in the Pacific Northwest. I examined the stomach contents of 20 Fulmars: five from Washington (salvaged from the beach in fall 2009) and fifteen from Oregon (supplied by Sharnelle Fee at the Wildife Center of the North Coast: http://www.coastwildlife.org/Home.html).


I found that 90% of specimens contained plastic, with an average of 21 plastic items and 0.34 grams of plastic per bird. Likely due to the high human population density of our area, this is notably more than in the Canadian high arctic, where studies report only 33% of Fulmars containing plastic (Mallory 2008). However, our study showed similar amounts of plastic to recent studies in the North Atlantic – in 2003, researchers reported 95% of Fulmars as having an average of 29 items and about 0.35 grams of plastic (van Franeker et al. 2003).


While a third of a gram of plastic might not sound like a lot to us, who can hold as much in the palm of our hand, this can be a huge burden for birds the size of Fulmars. There aren’t any established standards or goals yet for the United States, but the Oslo & Paris Convention in Europe has established a goal to reach less than 2% of Fulmars in monitoring surveys containing more than ten plastic pieces. 45% percent of Fulmars in my study and 56% in the North Atlantic in 2003 (van Franeker et al. 2003) contained more than ten items. In short, neither the status of marine plastic debris in the Pacific nor the Atlantic is anywhere near a level considered to be manageable and healthy for marine life.


I also found that 95% of plastic items in the Fulmars were user plastics – things like fragments from consumer products, Styrofoam, and the occasional bit of sheet plastic from a grocery bag. Only 5% were pre-production industrial plastics – round pellets usually of white, beige, or brown color that haven’t yet hit the factories. This is similar to recently reported trends in Northern Canada (Mallory 2008), but opposite of trends reported for the North Pacific in the 1990’s, which found primarily industrial plastics in Fulmars and other seabirds (Robards et al. 1995; Blight & Burger 1997). This could either mean that consumer plastic debris has increased in the Pacific, or that industrial plastics have decreased. It seems likely that both may be the case, as increased regulation on shipping companies may have decreased industrial plastic spills while increased human population and consumerism may be causing increased input of litter into the ocean.

Most of the plastic particles in these Fulmar specimens were neutral colors, such as white and beige. This suggests that Fulmars eat plastics that may resemble food items, such as fish, squid, or crustaceans. However, no data is available regarding the color composition of marine plastic debris in the environment, so we can't really tell whether the high proportion of these neutrally-colored plastics in Fulmars are a result of selection by the Fulmars or just a representative sample of what's available in the environment.


In terms of differences in plastic accumulation within my sample, I found that juveniles from Oregon contained significantly more microplastics than the adults (P=0.033). This is consistent with findings of other researchers (van Franeker et al. 2003), and likely a result of the fact that parents regurgitate food to their offspring, probably transferring plastic along with it. Alternatively, the juveniles might be less selective than adults in "prey" selection. The accumulation in juveniles is highly concerning because plastic accumulation is thought to contribute to reduced growth and could have future implications for recruitment of adults in Fulmar populations.


The last variable I looked at was the difference in plastic accumulation between the sexes. I didn’t expect to see any difference, since males and females are a similar size, both contribute to feeding offspring, and presumably have the same feeding habits. Overall, my expectations were confirmed and there was no significant difference (P=0.27). However, when I compared only the contents of the ventriculi, or the bottom portion of the stomach responsible for mechanical digestion, males contained notably (although not quite significantly) more plastic (P=0.095). Further investigation will hopefully clarify this trend, but for now, we are left in some uncertainty and confusion as to why females might accumulate less microplastics than males.

This project was only a first effort to use Northern Fulmars for microplastic monitoring in the Pacific Northwest. Already, other students at the University of Puget Sound are planning to continue this research in the future, which will hopefully lend additional significance and applicability to these results. Most of all, the results of this study will become vastly more useful with continued monitoring in an effort to better understand trends in environmental levels and composition of marine plastic debris and its potential effect on wildlife.

References:
Blight L.K. & Burger A.E. 1997. Occurrence of plastic particles in sea-birds from the Eastern North Pacific. Marine Pollution Bulletin 34: 323-325
Mallory M.L. 2008. Marine plastic debris in Northern Fulmars from the Canadian high Arctic. Marine Pollution Bulletin 56: 1501-1504
Robards M.D., Piatt J.F. & Wohl K.D. 1995.Increasing frequency of plastic particles ingested by seabirds in the subarctic North Pacific . Marine Pollution Bulletin 30:151.157.
van Franeker J.A., Meijboom A. & de Jong, M.L. 2003. Marine litter monitoring by Northern Fulmars in the Netherlands 1982-2003. Wageningen, Alterra, Alterra-rapport 1093

Lydia Kleine, Curatorial Assistant, Slater Museum

Bio of the author: A biology student at the University of Puget Sound, I have worked as an assistant at Slater Museum for a year. This was a final project for a marine biology class. I will be graduating this month and looking for a job.

Result in press as of 8 Jul 2012 at http://www.sciencedirect.com/science/article/pii/S0025326X12001828