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Albatross-born loggers show feeding on deep-sea squids: implications for the study of squid distributions

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By Gaitlyn Malone, SRC intern

Deep-sea squids are considered to be an important prey source for many top marine predators including fish, marine mammals, and seabirds (Clarke, 1996). However, despite their importance in marine food web structures, there is relatively little known about the biology and ecology of these squids, due to lack of observations, as well as limited knowledge of when, where, and how top predators prey on them (Nishizawa et al., 2018). Albatrosses are just one seabird species that feed mainly on squid, including those deep-sea dwelling species. Since albatrosses feed by capturing prey on the surface of the water, how they are able to obtain deep-sea squid has long been a mystery.

Figure 1. Laysan albatross (Phoebastria immutabilis) near Kauai, Hawaii (Dick Daniels, Wikimedia)

Multiple methods for accessing these squid have been hypothesized including feeding on squid that are dead and floating after spawning, those discarded from fishing vessels and longliners, those regurgitated by cetaceans, those that are living and come to the surface at night, or those that are alive and aggregate at the surface near productive ocean fronts (Rodhouse et al., 1987; Thompson, 1992; Clarke et al. 1981; Imber, 1992; Xavier et al., 2004). A recent study examined the post-spawning floater, fishery-related, and oceanic front hypotheses using Laysan albatrosses that were breeding on Oahu, Hawaii (Nishizawa et al., 2018). Laysan albatrosses were determined to be a suitable species to test these hypotheses due to the fact that they feed on both on deep-sea dwelling squid species and Argentine squids (Illex argentines), which are often used as bait in the swordfish longline fishery in Hawaii. In order to perform this analysis, 38 birds that were raising chicks were fitted with GPS-loggers and camera-loggers during the early chick-rearing period in February and March of 2015. The GPS-loggers were positioned on the backs of the birds, while the camera-loggers were placed on either the back or the belly depending on whether the bird was brooding chicks. Images were only collected by the cameras during daylight hours and were used to identify any squid species the birds preyed on, whether those squid were alive or dead, and whether they were whole or fragmented. Camera images were also used to reveal if fishing vessels or cetaceans were present in the area.

Figure 2. Images of squids recorded by the camera-loggers attached to Laysan albatrosses (Nishizawa et al., 2018)

In total, 26,068 images were obtained from 26 trips of 20 birds. Of those images, squids were visible in 23 images which corresponded to 16 predation events from 7 trips of 7 birds. Fishing vessels were found to be present in 69 images. All of the squids observed from the camera-loggers were dead and floating at the surface of the water, with ten of the squids being found in fragments while the other six were whole. Since many deep-sea dwelling squid species spawn and then die, it is possible that some of the squids present in the recorded predation events were the result of spawning mortalities. Although fishing vessels were observed, none were present in the images obtained during feeding events and the squids that were preyed upon were much larger than bait species. Therefore, these predation events are most likely not related to fishing occurring within the area. Overall, it was determined that Laysan albatrosses tend to feed opportunistically and do not tend to concentrate their efforts to a particular area. Through the use of GPS and camera-loggers, this study demonstrates how beneficial these devices can be in collecting information on the distribution of deep-sea squid and the significant role they play in the diet of marine predators.

Works Cited

Clarke, M.R. 1996. Cephalopods as prey. III. Cetaceans. Philosophical Transactions of the Royal Society B 351: 1053-1065.

Clarke, M.R., J.P. Croxall, P.A. Prince. 1981. Cephalopod remains in the regurgitations of the wandering albatross Diomedea exulas L at South Georgia. British Antarctic Survey Bulletin 54: 9-21.

Imber, M.J. 1992. Cephalopods eaten by wandering albatrosses (Diomedea exulans L.) breeding at six circumpolar localities. Journal of the Royal Society of New Zealand 22(4): 243-263.

Nishizawa, B., T. Sugawara, L.C. Young, E.A. Vanderwerf, K. Yoda, Y. Watanuki. 2018. Albatross-born loggers show feeding on deep-sea squids: implications for the study of squid distributions. Marine Ecology Progress Series 592: 257-265.

Rodhouse, P.G., M.R. Clarke, A.W.A. Murray. 1987. Cephalopod prey of the wandering albatross Diomedea exulans.Marine Biology 96(1): 1-10.

Thompson, K.R. 1992. Quantitative analysis of the use of discards from squid trawlers by black-browed albatrosses Diomedea melanophris in the vicinity of the Falkland Islands. Ibis 134: 11-21.

Xavier, J.C., P.N. Trathan, J.P. Croxall, A.G. Wood, G. Podesta, P. Rodhouse. 2004. Foraging ecology and interactions with fisheries of wandering albatrosses (Diomedea exulans) breeding at South Georgia. Fisheries Oceanography 13(5): 324-344.

Using Fish DNA in Threatened Albatross Diets as a Marine Conservation and Management Tool

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By Elana Rusnak, SRC Master’s Student

There is an unavoidable interaction between seabirds and the fishing industry, which impacts them through feeding supplementation, resource competition, and incidental mortalities (McInnes et al., 2017).  However, resolving these problems is often difficult and requires many resources.  Sea-faring birds are attracted to the fish scraps that are discarded from fishing vessels, which oftentimes come from species that are not naturally a part of their diet.  Gaining access to this food source may cause an imbalance in food-web structure, allowing gull populations to inflate, or causing albatrosses to prioritize nutritionally-poor food due to its ease of capture (Foster et al., 2017).  Moreover, these fisheries may be targeting an important food source for these birds and decreasing their access to it.  Understanding the interactions between seabirds and fisheries is necessary for effective ecosystem management.

 

Figure 1:  A trawling boat fishing for bottom-dwelling fish to which birds would not normally have access. (Source: NOAA – en:Image:Trawling_Drawing.jpg, Public Domain, https://commons.wikimedia.org/w/index.php?curid=1232501)

 

In the past, the two main ways to assess seabird diet were looking at their stomach contents, and stable isotope analysis.  Unfortunately, neither of these methods yield species-specific results when it comes to what kinds of fish are in these birds’ diets.  Recently, a non-invasive process called DNA metabarcoding has been useful in providing high-level specificity in seabird diets when analyzing their waste products.  It is also a broad-scale technique, which increases the number of birds and populations that scientists can sample while decreasing the amount of work and time required to do so.

 

Figure 2: The black-browed albatross (Source: Ed Dunens – Black-browed Albatross, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=64498778)t

 

The black-browed albatross is found in the southern hemisphere, where its population has been significantly impacted by longline and trawl fisheries.  A group of researchers used DNA metabarcoding to assess 6 sites across their breeding range to determine their prey diversity over space and time, identify if any of their prey comes from areas in which there are known fisheries operations, and evaluate potential resource competition or food supplementation by fisheries.  Albatross waste was collected, and DNA was extracted from each sample, then cross-referenced with known fish DNA.  The researchers found that 91% of their diet consisted of bony fish, with a diversity of 51 species, but the overwhelming majority of birds mostly ate 4 primary species of fish.  Samples collected from the 6 breeding sites showed differences in bird diet between sites.  A few species of fish identified from the DNA barcoding only live in the northern hemisphere, indicating that these birds are sourcing this prey from fisheries that use those kinds of fish as bait.  Depending on the site, between 0-60% of the birds were consuming fishery discards.  A few breeding sites were negatively impacted by resource competition, where the fishery was targeting their food source and they therefore did not have access to their normal diets.  This study shows that DNA barcoding has provided a means for scientists to prove that improvements in discard management to reduce the number of birds that feed from these vessels would reduce incidental mortality and have major implications for some albatross populations (McInnes et al., 2017).

Works cited

Foster, S., Swann, R. L., & Furness, R. W. (2017). Can changes in fishery landings explain long-term population trends in gulls?. Bird Study, 64(1), 90-97.

McInnes, J. C., Jarman, S. N., Lea, M. A., Raymond, B., Deagle, B. E., Phillips, R. A., … & Gras, M. (2017). DNA metabarcoding as a marine conservation and management tool: a circumpolar examination of fishery discards in the diet of threatened albatrosses. Frontiers in Marine Science, 4, 277.

Does marine debris affect tourist perception and tourism revenue?

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By Casey Dresbach, SRC Intern

The top worldwide providers of ecosystem services of both leisure and recreation include coastal areas such as beaches and estuaries (Millennium Ecosystem Assessment, 2005). These natural environments are home to hundreds of thousands of marine organisms, all of which require clean domains to flourish, thrive, and grow in. Unfortunately, human pollution has made its way into these areas, as depicted in Figure 1. “Marine debris” can be defined as any solid, persistent, human-created waste that has been deliberately or accidentally introduced into a waterway or ocean from shorelines to the ocean floor (Oregon Coast STEM Hub, 2017). Not only does this breed of debris directly affect marine species ocean-wide, but current research is also showing that it is taking a toll on both tourism and tourists’ destination choices worldwide.

Figure 1

Dr. Sylvia Earle engaging with a Laysan albatross nesting among marine debris. (USFWS – Pacific Region, 2012)

Marine debris is complex in its nature and jeopardizes other coastal entities. The debris has a dual effect on both the marine life as well income generated from local tourism. The interaction between marine debris and tourism is complex because items may form in regions other than the places where the litter is stranded and where tourism occurs (Krelling, Williams, & Turra, 2017). Individuals visiting beaches and coastal regions are more likely so seek alternate destinations if their overall experience is not remarkably enjoyable, and a substantial amount of scattered litter may play into that alternative choice of destination.

The coast of Paraná state in southern Brazil is one of the most frequented tourist destinations in this region (Krelling, Williams, & Turra, 2017). Many tourists, such as second-home owners and users (SHOU) and non-recurrent vacationers, frequent this Brazilian coast. A single SHOU is an individual or group of individuals who have an additional property, or vacation home elsewhere. And a non-recurrent tourist is an individual who has no territorial tie to a destination – is interested in vacation without having loyalty of a piece of land. In a recent study by researchers Allan Krelling, Allan Williams and Alexandra Turra, both the perceptions and reactions of these two distinct groups of beach users were compared. More than 70% of the visitors are SHOU. In fact, some of Paraná’s cities are dependent on property taxes from these second homeowners as well as the expenditures spent by the non-recurrent tourists on services such as food, activities, and other conveniences. Collectively, the two user groups and their tourism revenue drive the economy in the coastal area.

Figure 2

(a) Depicts the entire coastal region of Paraná State in southern Brazil. (Top right) Pontal Do Sul, a highly frequented estuarine beach in the coastal region of southern Brazil. (Bottom right) lpanema, a highly frequented open ocean beach in the coastal region of southern Brazil (Krelling, Williams, & Turra, 2017).)

The study compared both the perceptions and reactions of the two user groups. SHOU and non-recurrent tourists were administered a questionnaire to determine socioeconomic characteristics at two Brazilian sub-tropical beaches: Pontal do Sul and Ipanema, exhibited in Figure 2. Pontal do Sul is an estuarine beach and Ipanema is an open-ocean beach, which is more frequented by non-recurrent tourists. The ultimate goal of the questionnaire was to characterize these beach users’ socioeconomic characteristics such as yearly income, level of education, daily per person expenditure, frequency of trips and period of permanence (Krelling, Williams, & Turra, 2017). The survey also examined perceptions and reactions, especially those regarding the potential negative economic impacts of marine debris. Pontal do Sul and Ipanema were selectively chosen because of their varying geographical characteristics, ultimately adding more variability to the study set.

The general findings showed that SHOU might have a different reaction towards the marine debris than the average tourist. This can be linked to their loyalty to the destination, specifically tied to the property they have there. Results did show, however, that if debris were to reach a significant amount (>15 items/m2), more than 85% of beachgoers would look elsewhere when searching for a coastal region to vacation (Krelling, Williams, & Turra, 2017). If this were the case the stranded litter would threaten the Brazilian economy by reducing local tourism income by 39.1%, (Krelling, Williams, & Turra, 2017) which would present losses up to $8.5 million a year.

In order to improve beach users’ experience, moving forward, an issue like marine debris should be prioritized. Marine debris can be a stressor that impacts coastal tourism worldwide. An evaluation of economic impacts caused by litter presence is a unique approach to analyzing how to minimize the threat litter may pose to tourism revenue. Some factors that may influence a visitor’s beach choice may include beach length, scenery, water quality, amenities (restaurants, shops, etc.), and quantity of litter. The additive effect of these factors determines the overall impression the trip will leave on the visitor. Stranded beach litter is considered to be one of the five most important aspects regarding beach quality in Europe, USA, Mexico, and the Caribbean (Krelling, Williams, & Turra, 2017). More research should be done in order for authorities to decide how to best go about balancing investments to remove marine litter and minimize the potential reduction of tourism revenue. Through integrated planning, the sources of litter can be determined and preventive strategies can be put into play. This would help to avoid a reduction in environmental quality and income generated from tourism.

Works Cited

Krelling, A. P., Williams, A. T., & Turra, A. (2017, August 15). Differences in perception and reaction of tourist groups to beach marine debris that can influence a loss of tourism revenue in coastal areas. (H. Smith, Ed.) Marine Policy.

Millennium Ecosystem Assessment. (2005). Ecosystems and Human Well-being: Synthesis. Washington, DC: Island Press.

Oregon Coast STEM Hub. (2017). Marine Debris – Composition and Abundance. (L. C. Schools, O. C. Newport, N. M. Program, & S. G. (Oregon), Producers) Retrieved from Conserve Wildlife New Jersey:
http://oregoncoaststem.oregonstate.edu/marine-debris-steamss/md-grades-4-5/composition-and-abundance

USFWS – Pacific Region. (2012, January 11). Dr. Sylvia Earle talks to an albatross nesting among marine debris. (A. Collins, Producer) Retrieved from Wikimedia Commons: https://commons.wikimedia.org/wiki/ File:Dr._Sylvia_Earle_talks_to_an_albatross_nesting_among_marine_debris.jpg

A comparative analysis of the behavioral response to fishing boats in two albatross species

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By Andriana Fragola, SRC Intern

This paper examines the behavior of the Wandering Albatross (WA) and Black-Browed Albatross (BBA), and how they are affected by the toothfish longline fleet in Kerguelen and Crozet (Collet et al. 2017). To do this, lightweight GPS loggers were attached to adult albatrosses of both species to track their movements. To track the fishing boats, VMS data was provided to the researchers which allowed them to log their movements (Collet et al. 2017).

Calculations were done to establish the maximal distance that birds were seen flying towards the fishing boats. To isolate the different behaviors of the albatross the researchers established “encounter” as well as “attendance” behaviors to assess the responses of the birds to these fishing vessels (Collet et al. 2017). Encounters were defined as more by chance when the birds were in flight, while attendance behavior was defined as sitting in the water within a close range of the vessels (Collet et al. 2017).

Figure 1

[Source: Collet et al. 2017]

Results demonstrated that the Black-Browed Albatross (BBA) did not come into contact with fishing vessels as often as the Wandering Albatross (WA) (Collet et al. 2017). BBA also seemed to forage in areas that were a greater distance from the fishing vessels than WA (Collet et al. 2017). When the vessels were absent, BBA were not seen foraging in the regions where the vessels typically operate, while WA were (Collet et al. 2017).

Although WA are the larger and more dominant species, they were not observed pursuing the fishing vessels as much as the researchers had expected (Collet et al. 2017). BBA had an 80% chance of being attracted to fishing vessels, while WA had a lesser 60% chance of being attracted to the boats (Collet et al. 2017).

There were apparent differences between these two species and their utilization of fishing fleets as a means for foraging (Collet et al. 2017). This paper suggests that the energetic needs of each species can be an indicator of the risks associated with foraging from anthropogenic sources (Collet et al. 2017).

Figure 2

[Source: Collet et al. 2017]

It is vital to understand how species are becoming reliant on anthropogenic sources for food because this can affect their nutritional health. The quality of the fish that albatross are getting from these fishing vessels may not have the nutritional value of the fish they typically hunt. Further, if generations of these animals become dependent on these unnatural food sources, this can lead to issues – if the availability of that source becomes compromised, and birds are reliant to the extent that they do not have the skill to forage on their own.

Work Cited

Collet, J., Patrick, S. C., & Weimerskirch, H. (2017). A comparative analysis of the behavioral response to fishing boats in two albatross species. Behavioral Ecology, 28(5), 1337-1347.

Conservation of Amsterdam Albatrosses

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By Samantha Owen, RJD Intern

This paper outlines the current conservation efforts for the Critically Endangered Amsterdam albatross (Diomedea amsterdamensis) and the threat posed by industrial longline fisheries. In 2007 a population survey estimated that there were only 167 Amsterdam albatrosses in the world.  This is largely because they are only found in one place, Amsterdam Island, in the southern Indian Ocean.  Their population declined dramatically in the 1960s and 1970s due to the increase in industrial longline fishing targeting bluefin tuna.  While diving below the surface of the water when feeding, birds can be accidentally hooked or entangled in the longlines.

Like most albatrosses, this species is a biennial breeder, which means they only breed every other year. In between breeding years, they spend the entire break year roaming at sea.  A successfully mated pair will produce only one egg per breeding year.  This means that with such a small population, any mortality could have a huge impact on the viability of this species.  The established threshold to trigger a population decline is a loss of more than six individuals to bycatch per year. The potential number of individuals removed from the Amsterdam albatross population each year due to longline fishing is 2-16 depending on whether mitigation measures such as tori lines, plastic streamers trailing from the back of the boat used to scare birds away, were systematically employed.

amsterdam albatross

This paper quantifies the potential threat from industrial longline fishing fleets to the Amsterdam albatross based on time of year and life stages.  It shows that even though the Amsterdam albatross is potentially in contact with longline fisheries at every stage of its life, non-breeding individuals have a much higher susceptibility due to their significantly increased roaming area during their break year at sea. The time of year when Amsterdam albatrosses are at the highest risk for mortality as a result of bycatch in longlines is the austral winter (July, August, September) when fishing fleets are targeting albacore and other tunas.

The Taiwanese longline fishing fleet poses the greatest threat to Amsterdam albatrosses, followed closely by the Japanese fleet. One reason it is thought that the Taiwanese fleet has such a high impact on the Amsterdam albatross is because they deploy the most longlines in the waters immediately adjacent to the species’ home, Amsterdam Island.

In conclusion, this paper states three recommendations for further conservation efforts. First, increasing the coverage of fishing operations by dedicated observers in the distribution range of the Amsterdam albatross during the austral winter.  This would ensure the successful implementation of bycatch mitigation measures such as tori lines. The second recommendation is for Regional Fisheries Management Organizations (RFMOs) such as the Indian Ocean Tuna Commission (IOTC) to require all operating vessels to report ring recoveries.  All Amsterdam albatrosses have been fitted with leg bands (rings) identifying each individual. Although it would not directly prevent bycatch, reporting all recovered rings would allow scientists to more accurately define population-specific bycatch patterns in regional areas resulting in more targeted conservation efforts.  The third recommendation is to implement regulations on fishing efforts in the waters surrounding Amsterdam Island during the austral winter.  The combination of these three conservation efforts would allow the world’s only population of the Amsterdam albatross to grow and prevent any further decline that might very well result in the extinction of the species.

 

References:

Thiebot J.B., Delord K., Barbraud C.B., Marteau C., Wemerskirch H. 2015. 167 individuals versus millions of hooks: bycatch mitigation in longline fisheries underlies conservation of Amsterdam albatrosses. Aquatic Conservation: Marine and Freshwater Ecosystems. DOI: 10.1002/aqu.2578

Challenges in seabird by-catch mitigation

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By Hanover Matz, RJD Intern

In this paper, the authors comment on the current conservation status of seabirds and attempts to limit seabird deaths due to by-catch. Two species of seabirds, the albatrosses and the petrels, are particularly vulnerable to the detrimental effects of fisheries such as longlining. These birds normally lay only one egg per clutch and breed infrequently. They have long maturation and generation times compared to other birds, making it more difficult for their populations to recover from high mortality. They are also capable of flying long distances in search of food, crossing many different marine environments. This makes it difficult to implement conservation methods that can protect these birds in every part of the world they inhabit. Some of these species are already considered endangered or critically endangered. In order to fully protect them, an international effort is necessary.

A wandering albatross (Diomeda exulans) off Tasmania, Australia. Photo courtesy of JJ Harrison via Wikimedia Common

A wandering albatross (Diomeda exulans) off Tasmania, Australia. Photo courtesy of JJ Harrison via Wikimedia Commons

Seabirds and human fisheries come into conflict in many of the most productive regions of the ocean, specifically around New Zealand and Australia, the Humboldt Current off Chile, Peru, and Ecuador, the North Pacific, and South Africa. Seabirds are known to be killed as accidental by-catch in longline fisheries, and growing evidence has shown incidental catch of seabirds by trawlers. One difficulty in assessing whether trawling or longlining presents a greater threat to seabirds is the low proportion of entangled seabirds actually recovered from trawling gear. If the birds that collide with the gear cannot be retrieved, it is hard to assess the impact the fishery has. Refining the collection of data on how many seabirds are killed by longlining and trawling will improve conservation efforts.

In South Africa, the use of bird-scaring lines (BSLs) in fisheries has been shown to reduce the mortality of seabirds up to 95%. The trawl fishery previously had proportionally high incidental catches of albatrosses, making this a significant success in terms of protecting threatened species. However, to fully determine how well seabird mortality has been reduced, better data needs to be collected on both the level of by-catch and fishing effort. To reduce the by-catch of seabirds and improve conservation worldwide, the authors stress four important strategies. First, mitigation methods need to be improved with better data and techniques, considering each fishery individually and adapting the methods as necessary. Second, the quality of data collected needs to be increased by improving the programs used to collect it. Third, the fishing industry needs to be engaged by implementing and enforcing by-catch reduction, as well as cooperating to suit the needs of both the fishery and conservation. Finally, cooperation between governments, administrators, and decision makers is necessary to promote better fishing practices and conservation measures. In some fisheries, seabird by-catch mitigation is minimal or nonexistent. While trawling and longlining have been addressed, the effects of purse-seine and gill net fisheries are poorly understood. The threat posed by small scale and artisanal fishing fleets has also not been widely considered. If threatened seabird species are to be protected, it will require both national and international efforts. By improving the science behind the conservation, and cooperating with both governments and fisheries, scientists and conservations will be better able to address this conservation issue in the coming future.

References

1. Favero, M., & Seco Pon, J. P. 2014. Challenges in seabird by‐catch mitigation. Animal Conservation, 17(6), 532-533.