A GIS Analysis of Marine Debris in the North Pacific Gyre and Occurrence of Plastic Debris in the Stomachs of Longnose Lancetfish (Alepisaurus ferox)

1、a gis analysis of marine debris in the north pacific gyre and occurrence of plastic debris in the stomachs of longnose lancetfish (alepisaurus ferox)lesley jantzm.s. plan b thesis proposaladvisor: dr. greg brulanddepartment of natural resources and environmental managementabstract:marine debris is c

2、ollected, distributed and deposited by the currents and drifts of the north pacific gyre. debris, composed mainly of plastics and derelict fishing gear, accumulates in the north pacific subtropical convergence zone, a region near the hawaiian archipelago, where winds and currents diminish. this plas

3、tic debris is slow to decay and has become a persistent threat to the marine biota. consequently, the degradation of these marine ecosystems in the pacific is widespread and impacts all trophic levels. this project proposes to (1) analyze spatial and temporal variability of marine debris in relation

4、 to positional data for endangered sea turtles and protected seabirds; (2) investigate the association of marine debris and the surface chlorophyll concentrations; (3) examine the stomach contents of longnose lancetfish (alepisaurus ferox) for presence of plastic debris; (4) quantify plastic in the

5、longnose lancetfish gut contents and; (5) investigate relationships between weight and length of longnose lancetfish and their plastic content. positional data and fish specimens will be collected by the national oceanographic and atmospheric administration (noaa) fishery observer program. airborne

6、technologies will provide positional data on marine debris tagged with transmitters and surface chlorophyll concentrations will be downloaded from the noaa website ocean watch, bloom watch 180. the longnose lancetfish sampling will involve fishery observers to systematically sample every third lance

7、tfish captured on the longline. each fish will be measured and weighed before stomach contents are removed and inspected. a pilot study will be underway in may to evaluate the efficiency of the sampling design and analysis. to achieve optimal variability, i will sample 20 to 30 trips from may 2010 t

8、o december 2010. the following hypotheses will be tested: (1) the marine debris will exhibit overlap in space and time with the positional data of recorded sea turtle and seabird longline fishing interactions. marine debris will be associated with a chlorophyll front (a zone between waters of extrem

9、e surface chlorophyll concentrations); (2) plastic will be present in the stomachs of the longnose lancetfish sampled; (3) longnose lancetfish longer in length and greater in weight will have more plastic present in their stomachs than shorter and smaller fish.introduction:the aggregation of marine

10、debris in the north pacific gyre has been estimated to be the size of texas. it has been vividly described as the pacific trash vortex, a swirling sewer in the north pacific, a garbage patch and a plastic soup (moore, 2003). marine debris is a problem of global significance that affects oceans, coas

11、tlines, beaches and seafloors at all depths (williams et al., 2005). according to coe and rogers, “marine debris is any manufactured or processed solid waste material (typically inert) that enters the marine environment from any source” (1997). atmospheric, oceanographic and cosmic influences in con

12、currence with geostrophic currents of the north pacific gyre generate a mechanism that accumulates and transfers marine debris from the greater north pacific and the coastlines of north america and japan (kubota 1994). within the gyre, an area of convergence with high atmospheric pressure forces deb

13、ris to accrue and multiply in quantity (moore et al. 2001).early on, the threat of marine debris as a potential hazard was considered trivial due to the perceived abundance of marine life and vastness of the oceans (laist 1987). it was not until the 1970s, that plastic was perceived as a widespread

14、marine pollutant or recognized as a threat to marine species (azzarello and van vleet 1987). increased knowledge of the mechanical effects debris has on marine life justifies recognition of marine debris as a significant form of ocean pollution (laist 1987). marine animals can become entangled in op

15、enings or loops of drifting debris and ingest fragments of man-made materials. once ingested, plastic debris may block the digestive tract or remain in the stomach and reduce the drive to forage, cause ulcerations to the stomach lining and become a source of toxic chemicals (day et al. 1985). any an

16、imal weakened by loss of nutrients or toxic inputs become susceptible to predators and disease. hoss and settle explain, “for marine fishes, the ingestion of plastic debris and its subsequent effect is not well documented, but it is assumed that they, like other marine animals, will be unable to dis

17、tinguish between normal prey and small pieces of plastics.” most literature that describes plastic found in the stomach of fish is incidental to the main objective of the study. for example, in a food habit study of longnose lancetfish by kubota and uyeno (1969), 78 pieces of plastic and rubber were

18、 found in the stomachs of 36 specimens. jackson et al. (2000) studied the diet of the southern opah (lampri immaculatus) and discovered a high occurrence of plastic in the stomachs of 10 specimens, 14% of the total of stomachs analyzed. in a comparative food study of yellowfin tuna (thunnus albacare

19、s) and blackfin tuna (t. atlanticus), manooch and mason (1983), found a 31.6% frequency of non-food items (plants, feathers, lobs of tar and plastics) in the stomachs of yellowfin tuna compared to 15.7% in blackfin tuna.the stomach analysis component of my research will help to fill a void in resear

20、ch on the incidental ingestion of plastics by marine fish. this analysis will create baseline data on the occurrence of plastic in stomachs of pelagic fish, specifically longnose lancetfish. this study may serve as a basis for future research on the affects of ingested debris; blocking and damage to

21、 the digestive tract and depending on its chemical composition, toxic effects, bioaccumulation and biomagnification. this study will assist resource managers in their exploration of marine debris and the extensive consequences.the hawaii longline deep-set fishery is an ideal source for the collectio

22、n of longnose lancetfish for stomach analysis. the fishing grounds are vast, covering 15 million km2 of the central north pacific. although, the deep-set fishery targets bigeye tuna (thunnus obeseus), non-target species also referred to as by-catch, are captured and discarded or kept and sold. longn

23、ose lancetfish are frequently encountered by-catch, generally discarded and only occasionally consumed on the vessel but not sold at the auction.literature review: plastics- plastics are synthetic, petroleum based, organic polymers that have made a steadfast hold in our society based on their abilit

24、y to resist bacterial and oxidative decay (moore 2003). it is these properties that make plastic so desirable as well as a menace when they become a component of marine debris. plastics are problematic because they float, are non-biodegradable, and only breakdown upon exposure to ultraviolet radiati

25、on. photodegradation is a slow process that begins with surficial cracking and embrittlement of plastic into fragmented remains (williams et al. 2005). studies have shown that the rates of degradation and weathering of plastics are less when floating in the marine environment (williams et al. 2005).

26、 although, some plastics are being treated with additives to enhance photosensitive degradability upon ultraviolet exposure, this effort may be easily discounted due to an increase of plastic production and discards (azzarello and van vleet 1987). when plastics finally do degrade, the fragmented pie

27、ces may potentially absorb toxic chemicals, disperse into the water column and may be ingested by jellyfish and salps possibly transmitting toxins throughout the food web (moore 2003). production of plastic resin in the united states has dramatically increased since the 1960s from 2.9 million tons t

28、o 21.7 million tons in 1985 (pruter 1987). polyethylene, polystyrene, polyvinyl chloride and polypropylene are the most common types of plastic marine debris (pruter 1987). examples of plastic pollutants collected in the north pacific subtropical gyre includes: lighters, bottle caps, cups, bags, pla

29、stic sheets (fig. 1a) and pre-production plastic pellets. the pre-production pellets, which resemble small cylindrical disk shapes less than 4mm in size, are the bulk material used to formulate plastic materials (azzarello and van vleet 1987). in general, plastic marine pollution can be characterize

30、d as packaging material, convenience items and raw plastics. sources of these plastics are attributed to ship generated litter, debris in rivers and city drainage systems and trash left behind by beachgoers (derraik 2002).derelict fishing gear- donohue et al. explains, “characterized by distinct bat

31、hymetry, relative geography, and critical habitat for endangered species, debris having maritime origins may pose the greatest threat to ecosystem health” (2001). maritime debris may consist of trawl, seine, cargo and gill nets constructed of monofilament and multifilament as well as longline monofi

32、lament and hawser. these nets vary in stretch mesh, twine diameter, number of strands and types of construction such as: twisted knotted, twisted-knotless, braided knotted, braided knotless and double-stranded (timmers et al. 2005). the use of synthetic materials initiated a major revolution in the

33、fishing industry.twine originally used to fabricate netting consisted of natural fibers such as cotton, flax, linen, manila, sisal and hemp have been replaced by synthetic materials like polypropylene, polyethylene and nylon (timmers, et al. 2005). nets constructed of synthetic material eventually l

34、oose their strength; however they do not rot like materials of natural fiber (uchida 1985). in 1949, the japanese were the first fisherman to incorporate synthetic fibers into the construction of gill and surrounding nets (uchida 1985). fifteen years later, synthetic fiber nets accounted for 100% of

35、 all netting material manufactured in japan (uchida 1985).derelict fishing gear (dfg) is intentionally discarded or unintentionally lost due to storms or active fishing activities (ingraham and ebbesmeyer 2001). this accumulation of derelict fishing gear is attributed to the trawl, gillnet, and sein

36、e fisheries of the greater north pacific ocean. potential sources of derelict trawl gear (fig. 1b) include: domestic and foreign fishing in the gulf of alaska, bering sea, the western coast of north america, japanese, russian, chinese, korean and taiwanese waters (donohue et al. 2001). potential sou

37、rces for monofilament gillnet include: california, oregon and mexico driftnet fisheries (donohue et al. 2001).figure 1a. plastic tarp retrieved from figure 1b. derelict fishing gear hauledthe ocean on to a longline vessel.aboard a longline vessel.north pacific gyre- ocean currents are a directed mov

38、ement of atmospheric, oceanographic and cosmic influences: wind, temperature, salinity, the rotation of the earth and the cycle of the moon (gradwohl and feldman 2009). the horizontal movements of ocean surface waters mirror the wind circulation of the atmosphere. large scale, elliptical current sys

39、tems stretching from east to west are called gyres. there are four large currents in the pacific ocean: north pacific, california, north equatorial and kuroshio (fig. 2). these currents move in a clockwise direction and create the north pacific subtropical gyre.within in the north pacific subtropica

40、l gyre, is the north pacific transition zone (tz). this tz is located between the subtropical gyre with an estimated surface chlorophyll concentration of 0.25 mg m-3 (pollovina et al. 2001). separating the two gyres is a sharp chlorophyll front that shifts seasonally from 30n in the winter to 45n in

41、 the summer (pollovina et al. 2001). the zone between the two chlorophyll extremes is referred to as the transition zone chlorophyll front (tzcf) (polovina et al. 2001). the subtropical convergence zone (stcz) is the boundary between the nutrient-rich waters in the northern tz and the nutrient-poor

42、waters in the southern olgiotrophic zone (pichel et al. 2007). the location of the transition zone and the associated subtropical convergence zone has spatial and temporal variations that are more obvious during el nio years (donohue and foley 2007). figure 2. location of the hawaiian archipelago re

43、lative to the main pacific ocean currents and the north pacific subtropical convergence zone.marine debris accumulation- the accumulation mechanism for marine debris in the north pacific gyre can be divided into three steps: the convergence of floating matter in the mid latitudes due to ekman transp

44、ort, the transport of this mater from western pacific to the eastern pacific due to the north pacific current, and the accumulation of debris north of hawaii due to the ekman convergence in relation to the subtropical transition zone (kubota 1994). the stcz is known has the “horse latitudes,” a regi

45、on of variable to low wind stress avoided by sailors due to the lack of wind necessary to sail (moore 2003). marine debris may reside in this area for extended periods because of the weak ekman drifts and weak geostrophic currents (kubota 1994). noaa marine debris program- to research and mitigate t

46、he accumulation of marine debris and monitor debris behavior, the noaa marine debris program (mdp) was established in 2006 with a primary mission of identifying, reducing, and preventing debris from entering into the marine environment (noaa mdp, 2009). debris management programs within noaa began t

47、o surface in the mid 1980s with the marine entanglement research program. the mdp was not officially launched until 2005 and legally established by president bush in 2006 under the research, prevention and reduction act (noaa mdp, 2009). the noaa mdp program utilizes an ecosystem-based approach and

48、co-chairs with the epa on the marine debris coordinating committee (mdcc). the mdcc is an interagency collaboration of federal and state agencies tasked with developing multi-disciplinary strategies to reduce sources and impacts of marine debris. the strategic goals of the noaa mdp include: mapping

49、debris, assessing debris impacts, removing and disposing debris and increasing public awareness of marine debris in the marine environment (noaa mdp, 2009).sea turtles- turtles such as the loggerhead sea turtle (dermochelys coriacea), migrate great distances during their lives in the oceans from the

50、 shores of australia and japan to their foraging habitat in the eastern pacific (polovina et al. 2000). during this migration the probability of an encounter with marine debris is likely especially when these turtles seem to be attracted to similar gyres known to transport marine debris near the haw

51、aiian archipelago. in 1997 and 1998, nine loggerhead sea turtles were tagged with satellite telemetry by noaa observers in the central north pacific and paired with satellite remote sensing data for environmental parameters (polovina et al. 2000). the turtles were tracked travelling against prevaili

52、ng currents along two convergent fronts within the north pacific transition zone, located between the subtropical gyre in the south and the subarctic gyre in the north (polovina et al. 2000). these turtles are attracted to these waters due to the large amount of preferred prey.figure 3. green sea tu

53、rtle (chelonian figure 4. hawksbill sea turtle (eretmochelysmydas) entangled in dfg. photo imbricata) shell remains in dfg. photo courtesy of greg schorr, noaa, courtesy of heath larner, noaa observer.cred. unfortunately, turtles foraging for food may ingest floating plastic mistaking it for buoyant

54、 prey such as the jellyfish. a necropsy of an adult leatherback sea turtle incidentally killed by a swordfish longline off terceira island in the azores, revealed six pieces of soft plastic together with a hard plastic belt and small plastic cap in the anterior part of the intestine (barreiros and b

55、arcelos 2001). although, this turtle was in good health and the plastic did not cause any apparent harm, had it lived longer the plastic may have caused sever ulcerate processes and possibly tissue necrosis (barreiros and barcelos 2001). according to balaz, even if the plastic debris does not cause

56、mechanical blockage the turtle is still adversely affected due to loss of nutrients, and absorption of toxic plasticizers (1985). turtles are also likely to become entangled in marine debris, which may prohibit normal feeding, diving, breathing or other basic behaviors (balaz 1985). netting or line

57、that is constricting may even create lesions on the animal and constrict blood flow to limbs resulting in necrosis (balaz 1985). seabirds- like sea turtles, seabirds tend to mistake plastic debris as food. the type of foraging behavior and characteristics of prey play a key role in the amount of pla

58、stic ingested for particular species (laist 1987). bird species in the order, procellariiforms, such as the black-footed albatross (phoebastria nigripes) and laysan albatross (p. immutabilis), who forage by surface-seizing or pursuitdiving and primarily feed on crustacean and cephalopods, have the highest tendencies to ingest plastic (day at el. 1985). in a study in alaska on stomach contents of seabirds, 85% of the plastics ingested were small in size and of the light brown color range and 8% were i