Content uploaded by Henry S Carson
Author content
All content in this area was uploaded by Henry S Carson on Apr 23, 2014
Content may be subject to copyright.
1 23
Marine Biology
International Journal on Life in Oceans
and Coastal Waters
ISSN 0025-3162
Mar Biol
DOI 10.1007/s00227-014-2432-8
Relationship of diversity and habitat area
in North Pacific plastic-associated rafting
communities
Miriam C.Goldstein, Henry S.Carson &
Marcus Eriksen
1 23
Your article is protected by copyright and
all rights are held exclusively by Springer-
Verlag Berlin Heidelberg. This e-offprint is
for personal use only and shall not be self-
archived in electronic repositories. If you wish
to self-archive your article, please use the
accepted manuscript version for posting on
your own website. You may further deposit
the accepted manuscript version in any
repository, provided it is only made publicly
available 12 months after official publication
or later and provided acknowledgement is
given to the original source of publication
and a link is inserted to the published article
on Springer's website. The link must be
accompanied by the following text: "The final
publication is available at link.springer.com”.
1 3
Mar Biol
DOI 10.1007/s00227-014-2432-8
ORIGINAL PAPER
Relationship of diversity and habitat area in North Pacific
plastic‑associated rafting communities
Miriam C. Goldstein · Henry S. Carson ·
Marcus Eriksen
Received: 21 October 2013 / Accepted: 20 March 2014
© Springer-Verlag Berlin Heidelberg 2014
including the coral pathogen Halofolliculina spp. In con-
cordance with classic species–area curves, the number
of rafting taxa was positively correlated with the size of
the raft. Our findings suggest that diversity patterns on
plastic debris are compatible with the concept of island
biogeography.
Introduction
Naturally occurring floating objects in the pelagic environ-
ment have long played host to a suite of specialized species
(Thiel and Gutow 2005a). These substrates, such as float-
ing algae, pumice, and wood, provide transport and habi-
tat for benthic organisms (Donlan and Nelson 2003; Thiel
and Gutow 2005b; Bryan et al. 2012). In recent decades,
natural rafts have been augmented by anthropogenic debris
comprised primarily of non-biodegradable plastic polymers
such as hard thermoplastic, foam, synthetic rubber, and
fiberglass (Derraik 2002; Barnes et al. 2009).
Plastic debris was first detected in the open ocean in the
early 1970s (Carpenter and Smith 1972; Venrick et al. 1973;
Wong et al. 1974) and has now been observed all over the
world (Thiel and Gutow 2005a). Plastic enters the marine
environment through improper disposal (e.g., litter) or acci-
dental loss (e.g., fishing gear; U.S. Environmental Protec-
tion Agency 2011). Debris from land-based sources is most
common near highly populated areas, while debris from
marine sources is most common on remote shores (Hammer
et al. 2012). However, as debris is exposed to UV light and
physical weathering, it fragments into small pieces, termed
microplastics, that are frequently less than 5 mm in diameter
(Andrady 2011; Hidalgo-Ruz et al. 2012). Microplastics
now comprise the vast numerical majority of debris in the
ocean (Goldstein et al. 2013) though larger objects that can
Abstract Plastic and other anthropogenic debris (e.g.,
rubber, tar) augment natural floating substrates (e.g., algal
rafts, pumice) in the open ocean, allowing “islands” of
substrate-associated organisms to persist in an otherwise
unsuitable habitat. We examined a total of 242 debris
objects collected in the eastern Pacific in 2009 and 2011
(32–39°N, 130–142°W) and the western Pacific in 2012
(19–41°N, 143–156°E). Here, we ask: (a) What taxa
are associated with plastic rafts in the North Pacific?
and (b) Does the number of taxa associated with plas-
tic debris vary with the size of the debris “island?” We
documented 95 rafting taxa from 11 phyla. We identified
several potentially invasive plastic-associated rafting taxa,
Communicated by F. Bulleri.
Electronic supplementary material The online version of this
article (doi:10.1007/s00227-014-2432-8) contains supplementary
material, which is available to authorized users.
M. C. Goldstein
Scripps Institution of Oceanography, University of California San
Diego, La Jolla, CA, USA
Present Address:
M. C. Goldstein (*)
California Sea Grant, La Jolla, CA, USA
e-mail: miriam.goldstein@gmail.com
H. S. Carson
University of Hawaii at Hilo, Hilo, HI, USA
Present Address:
H. S. Carson
Washington Department of Fish and Wildlife, Olympia, WA,
USA
M. Eriksen
5 Gyres Institute, Los Angeles, CA, USA
Author's personal copy
Mar Biol
1 3
support a more extensive rafting community are far from
uncommon (Titmus and Hyrenbach 2011, Ryan 2013).
The composition of the rafting assemblage depends
on the type of object, its stability, and the supply of prop-
agules (Thiel and Gutow 2005b). In general, artificial sub-
strates do not host the same communities as natural sub-
strates (Tyrrell and Byers 2007; Pister 2009; but see Bravo
et al. 2011). In the case of floating objects, biotic rafts
(e.g., wood, detached kelp) do not float for as long as abi-
otic rafts (e.g., plastic, tar, pumice), but do provide a food
source for rafting organisms, and therefore may be more
successful at transporting a variety of species (Donlan and
Nelson 2003; Thiel and Gutow 2005b). Items with a com-
plex surface (e.g., pumice, macroalgae holdfasts) may pro-
vide better habitat than items with a smooth surface (e.g.,
plastic bottles; Thiel and Gutow 2005b). The rotational
stability of the rafting object may also affect the diversity
of the attached assemblage—pieces with fewer changes in
orientation have greater species richness and cover than
less stable pieces (Bravo et al. 2011; Bryan et al. 2012).
Fouling also increases the specific density of the raft,
which may cause sinking in the water column and poten-
tially a subsequent rise to the surface if fouling organisms
die or are removed by predators (Ye and Andrady 1991;
Moret-Ferguson et al. 2010), though fouling can also
help maintain the positive buoyancy of porous rafts (e.g.,
pumice, foam) by reducing gas permeability (Bryan et al.
2012). Lastly, the physical environment around the raft,
such as distance from shore or water temperature, may
be more significant to rafting species composition than
characteristics of the raft itself (Clarkin et al. 2012). For
example, rafts that were colonized in coastal waters may
have different species composition than rafts colonized at
sea (Astudillo et al. 2009), and the diversity of the raft-
ing community may be enhanced by encounters with lar-
val sources such as islands, reefs, and other shallow-water
habitats (Bryan et al. 2012).
Diversity patterns in open-ocean rafting assemblages,
particularly plastic-associated assemblages, are largely
unexplored. In many ecosystems, diversity is predicted
by the species–area curve, in which the number of species
increases as a function of available surface area, though
the shape of this curve has been a matter of some debate
(He and Legendre 1996). Species–area curves can be
explained by the concept of island biogeography, which
predicts that species diversity is a balance between arrival
of species through migration and the loss through extinc-
tion, both processes that vary with available habitat area
(MacArthur and Wilson 1963). While species–area rela-
tionships are one of the most widely observed patterns in
ecology, there are exceptions, such as the “small-island
effect,” in which the areas of the ecosystems observed
are all too small for a diversity pattern to be detected
(Lomolino 2000). It is unknown whether plastic-asso-
ciated rafting assemblages follow the species–area pat-
tern, particularly since organisms with certain life history
traits, such as suspension feeding, are more likely to be
successful rafters, especially on abiotic substrata such as
plastic (Thiel and Haye 2006).
The light weight and durability of plastic make it a
vector for the transport of non-indigenous species. For
example, a piece of flotsam with traces of tropical biota,
including self-fertilizing corals, was recently discovered
in the Netherlands (Hoeksema et al. 2012), and South-
ern Ocean bryozoans in reproductive condition were
found on a beached packing band in Antarctica (Barnes
and Fraser 2003). Benthic organisms such as bryozoans,
barnacles, and hydroids are commonly found on plas-
tic debris (Aliani and Molcard 2003; Barnes and Milner
2005; Farrapeira 2011). The particular vulnerability of
island ecosystems to invasions and the ubiquity of plas-
tic debris on the mid-Pacific islands makes lateral trans-
port of fouling species a matter of particular concern
in the North Pacific (McDermid and McMullen 2004).
Recently, a non-native hydroid and two ascidians were
recorded from debris collected in the Northwest Hawai-
ian Islands (Godwin et al. 2008). However, most studies
have examined beached material, not in situ debris (Win-
ston et al. 1997; Barnes 2002; Barnes and Fraser 2003;
Barnes and Milner 2005; Hoeksema et al. 2012; but see
Astudillo et al. 2009).
Even when debris does not carry organisms to dis-
tant shorelines, debris can provide abundant habitat to
fouling organisms. In coastal areas, abundance of float-
ing macroalgae varies between 1 and 1,000 items km−2,
occasionally even exceeding values of 10,000 items km−2
(Thiel and Gutow 2005a). High densities of abiotic sub-
strates can also occur in the open ocean—one eruption in
Tonga was estimated to release over 2.5 × 1012 individual
pumice clasts, more than 50 % of which were inhabited
by rafting organisms (Bryan et al. 2012). Floating micro-
plastic debris in the subtropical gyres can also reach high
densities, such as a median of 425,000 items km−3 in the
North Pacific subtropical gyre (Goldstein et al. 2012) and
a mean of 20,328 items km−2 in the North Atlantic sub-
tropical gyre (Law et al. 2010). This increase in habitat
has the potential to expand populations of open-ocean
rafting species, such as gooseneck barnacles (Whitehead
et al. 2011) and oceanic insects (Goldstein et al. 2012;
Majer et al. 2012).
In this study, we asked: (a) What taxa are associated
with drifting plastic in the North Pacific? (b) Does the num-
ber of taxa associated with plastic debris vary with the size
of the debris “island?”
Author's personal copy
Mar Biol
1 3
Methods
Samples were collected on three cruises, the 2009 Scripps
Environmental Accumulation of Plastics Expedition (SEA-
PLEX), the 2011 Algalita Eastern North Pacific Gyre Expe-
dition, and 2012 Western North Pacific Gyre Expedition
(Fig. 1).
For the 2009 samples, floating debris items were oppor-
tunistically collected by dip net (39 cm length × 33.5 cm
width, mesh 1 mm). If possible, the entire piece of debris
with attached fauna was preserved in either 5 % formalin
buffered with sodium borate or 95 % ethanol. An attempt
was made to preserve portions of most samples in both pre-
servatives to allow for both morphological and molecular
studies. When the item was too large to be preserved, the
item was either subsampled (e.g., portions of a tarp were
cut and preserved) or the fauna were removed and pre-
served separately (e.g., in the case of a large fishing buoy).
A subset of plastics collected using a standard manta net
(0.86 × 0.2 m) with 333-μm mesh (Brown and Cheng
1981), towed for 15 min at 0.7–1 m s−1, were also included
in this study. For smaller Manta-net-collected debris parti-
cles, 50 % aliquots of the net-collected samples were ana-
lyzed. Since splitting samples cause the less abundant larger
debris items to be undersampled, all Manta-net-collected
objects with a diameter of greater than 2 cm were included
in this study. For this reason, we found it practical to use the
2-cm cutoff to divide “fragments” from larger objects.
On the 2011 and 2012 expeditions, debris items were col-
lected by dipnet during timed debris observation periods or
opportunistically during other daylight sightings. Debris
items were inspected for attached organisms immediately and
then taken to shipboard laboratory for microscope inspection,
photography, and preservation. If possible, the entire piece
of debris with attached fauna was preserved in 5 % formalin
as on the 2009 cruise. Where not possible, organisms were
removed and preserved separately. Three floating masses of
nets, rope, and entangled debris were sampled differently. In
2011, the net mass was examined by divers in the water, who
noted associated fishes, collected fouling organisms oppor-
tunistically, and subsampled the materials for inspection on
board. In 2012, both net masses were inspected in the water
first and then hauled on board and dissected on deck for a
more thorough collection of fouling organisms.
In the laboratory, objects from the 2009 expedition were
examined for rafting fauna under a Wild M-5 dissecting
microscope. The preservative was also filtered through
150-μm Nitex mesh to retain non-attached biota. During
the 2011 and 2012 expeditions, organisms and small debris
were inspected and photographed on board using a Dino-
Lite Premiere digital microscope. All objects were pho-
tographed with in situ size references. Two-dimensional
surface area was digitally measured using the NIH ImageJ
software (Rasband 2012) and calibrated against manual
measurements. Because of the flattened shape of most
debris objects, we approximated total surface area by mul-
tiplying two-dimensional surface area by a factor of two. It
should be noted that this approach substantially underesti-
mates the total surface area of complex structures such as
rope clumps and net balls.
Fig. 1 Map of sampling locations and photographs of representa-
tive plastic debris. a Locations of debris collection in 2009 (circles),
2011 (triangles), and 2012 (diamonds). b Small plastic fragments
intermixed with the chondrophore Velella velella; collected August
10, 2009, 03:57 GMT, 32° 37.91′N, 140° 18.61′W. c Medium plastic
fragments with 15-cm ruler; collected August 11, 2009, 07:30 GMT,
32° 54.99′N, 140° 19.81′W. d A large tangle of intermixed fishing-
related nets, ropes, and buoys along with other hard plastic debris
(“rope clump”); collected May 12, 2012, 03:00 GMT, 22° 13.35′N,
155° 21.17′E
Author's personal copy
Mar Biol
1 3
Later identification of preserved specimens in the labora-
tory was made using dissection or compound microscopes.
All fauna were identified to the lowest possible taxonomic
level. When objects with different taxonomic resolutions
were compared, taxa were collated to comparable levels.
For example, Lepas pacifica, L. anatifera, and Lepas spp.
were counted as one taxon. To determine whether taxa had
previously been documented as rafting, we first consulted
the comprehensive lists of rafting taxa given in Thiel and
Gutow (2005b). If a given taxa were not listed in Thiel and
Gutow (2005b), we conducted a literature search to deter-
mine whether we could find other documentation of rafting
in the taxa. If we could not find such documentation, the
taxa were listed as “not previously documented as rafting.”
A complete list of debris locations and associated taxa is
given in Supplemental Table 1. We determined the feed-
ing type of each taxon from our own biological knowledge
and from reference to the literature as necessary. When
the feeding ecology of a specific taxon was unknown, we
assigned it to the most probable feeding type. For exam-
ple, an unidentified hydroid was classified as a “suspension
feeder.”
Statistics and figures were generated with the R statis-
tical environment, version R-2.13.1 (R Development Core
Team 2012). Debris object areas were log-transformed for
ease of display. We used the chi-square test to test whether
rafting assemblage traits (e.g., phyla composition, feeding
type) varied between cruises and years. We used Kendall’s
tau rank correlation coefficient to measure the strength of
dependence between debris size and number of taxa. For
one analysis, both taxa and debris area were linearized
using log transformations so that the relationship could be
more easily visualized, and analyzed using linear regres-
sion (Lomolino 2000) (Fig. 2).
Results
We examined a total of 242 debris objects and identified
95 associated rafting taxa (Table 1). The debris comprised
66 % rigid plastic fragments less than 2 cm in diameter,
21 % rigid plastic fragments or objects ranging from 2 to
100 cm in diameter, 7 % rope clumps, 3 % flexible sub-
strates (e.g., tarps), and 3 % expanded foam (e.g., “Styro-
foam”). Debris substrate area ranged from 2.54 × 10−7 to
15 m2, with a median of 1.18 × 10−4 m2.
Representatives of 11 phyla were found, with the most
abundant phylum being the Arthropoda, followed by Mol-
lusca and Cnidaria (Fig. 3a). The majority of these taxa
were suspension feeders, though omnivores, grazers, and
predators were also well represented (Fig. 3b). Slightly
more taxa were mobile than were sessile (Fig. 3c). Of all
95 identified taxa, 25 (26 %) had not been previously found
to occur in rafting assemblages (Fig. 3d, Table 1). No dif-
ferences in the composition of phyla, feeding type, and
mobile/sessile taxa were found between cruise years/loca-
tions (chi-square test, P > 0.5 for all tests).
We found a significant positive correlation between the
size of the debris object and the number of taxa found on
that object (Fig. 4a, Kendall’s tau, τ = 0.555, N = 242,
P < 0.001). This correlation remained significant when the
data were linearized through log transformation (Fig. 4b,
linear regression, r2 = 0.169, F1.66 = 48.69, P < 0.001), as
well as when the four largest items were removed (linear
regression, r2 = 0.086, F1.66 = 22.45, P < 0.001). When
cruises were examined separately (Fig. S1), there was a
significant positive correlation between debris size and
taxon richness in 2009 (Kendall’s tau, τ = 0.561, N = 208,
P < 0.001) and 2011 (Kendall’s tau, τ = 0.650, N = 13,
P = 0.003), but not in 2012 (Kendall’s tau, τ = 0.062,
N = 21, P = 0.710). We did not find a relationship between
distance offshore and number of taxa.
The eight most taxon-rich phyla also exhibited signifi-
cant positive relationships between object size and number
of taxa (Fig S2, Kendall’s tau P < 0.01 for all phyla). How-
ever, for the phyla that have few taxa (e.g., 1–3 taxa), these
relationships are sensitive toward incidentally occurring
individuals.
We noted a shallow parabolic shape, in both our overall
taxa–area semi-log curve and for some of the phylum-spe-
cific curves, such as Arthropoda and Bryozoa. Higher num-
bers of taxa were found on medium-sized objects (approxi-
mately 1 × 10−2 m2) as compared to slightly larger objects
(approximately 1 m2), though the largest objects (approxi-
mately 10 m2) retained the overall highest numbers of taxa.
Discussion
Composition of rafting assemblage
We found a diverse and widespread rafting assemblage
inhabiting North Pacific plastic debris. The majority of
taxa were known members of the rafting assemblage such
as Lepas spp. barnacles and membraniporid bryozoans,
but we documented 25 taxa that had not been previously
found in rafting assemblages. Many of the previously
undocumented taxa were from groups that are known to
be prolific and successful rafters, such as the bryozoans,
sponges, and peracarid crustaceans (Barnes 2002; Thiel
and Gutow 2005b). We were surprised to find a small
number of boring organisms rafting on pelagic plastic
debris composed of foamed polystyrene. These included
the bivalve Zirfaea, the shipworm Teredo, and a spha-
eromatid isopod. While boring organisms are known to
colonize rafts of biotic origin, such as wood and algae,
Author's personal copy
Mar Biol
1 3
they are relatively rare on plastic debris (Thiel and Gutow
2005b; Thiel and Haye 2006), although sphaeromatid iso-
pods are known to burrow in polystyrene floats in coastal
ecosystems (Davidson 2012).
Another organism of particular interest was the follicu-
linid ciliate (Halofolliculina spp.), found in abundance on
some western Pacific plastic debris. These ciliates are path-
ogens that cause skeletal eroding band (SEB) disease in
corals (Rodriguez et al. 2009). Though originally thought to
be limited to the Indian Ocean and South Pacific, SEB dis-
ease was discovered in Caribbean corals in 2004 (Croquer
et al. 2006) and in Hawaiian corals in 2010 (Palmer and
Gates 2010). The mechanism behind the spread of SEB
is not known (Croquer et al. 2006), but since the Hawai-
ian Islands are highly impacted by plastic debris collected
by the North Pacific subtropical convergence zone (Dam-
eron et al. 2007), it is possible that debris facilitated the
dispersal of Halofolliculina to this area. Like many rafting
substrates, plastic debris has the potential to disperse non-
ciliate pathogens, such as viruses, but the role of debris as
a disease fomite has been little studied (Maso et al. 2003;
Pham et al. 2012).
Fig. 2 Photographs of assorted debris. a Lepas barnacles growing on
buoy; collected June 22, 2012, 02:00 GMT, 29°11.9′N, 170°35.2′E.
b Lepas barnacles growing on a rope; collected May 14, 2012, 20:00
GMT, 26°26.56′N, 152°07.44′E. c Two Lepas barnacles and mem-
braniporid bryozoans growing on a toothbrush handle, collected June
17, 2012, 02:00 GMT, 15°26.3′N, 150°30.0′E. d A juvenile trigger-
fish C. maculata found associated with a bleach bottle, collected May
12, 2012, 21:00 GMT at 22°11.06′N, 155°22.07′E. e Close view of
fragment showing folliculinid ciliates and other organisms; collected
May 10, 2012, 22:15 GMT, 19°53.05′N, 155°04.22′E. f Close view
of folliculinid ciliates showing the two pericytostomial wings extend-
ing from the lorica, collected May 10, 2012, 22:15 GMT, 19°53.05′N,
155°04.22′E
Author's personal copy
Mar Biol
1 3
Table 1 Rafting taxa
Phylum Class Order Finest taxon identified Year
observed
Previously
documented as rafting
Annelida Polychaeta Aciculata Eunice spp. c 1
Annelida Polychaeta Amphinomida Amphinome rostrata c 1
Annelida Polychaeta Amphinomida Hipponoe gaudichaudi a, b 1
Annelida Polychaeta Phyllodcida Halosydna spp. b N
Annelida Polychaeta Phyllodocida Nereididae c 1
Annelida Polychaeta Phyllodocida Nereis spp. c 1
Annelida Polychaeta Phyllodocida Phyllodocidae c 1
Annelida Polychaeta Sabellida Salmacina spp. c N
Annelida Polychaeta Sabellida Subfamily Serpulinae c 1
Annelida Polychaeta Sabellida Subfamily Spirorbinae a, c 1
Arthropoda Malacostraca Amphipoda Caprella spp. a, c 1
Arthropoda Malacostraca Amphipoda Elasmopus spp. a 1
Arthropoda Malacostraca Amphipoda Hyalidae a 1
Arthropoda Malacostraca Amphipoda Isaeidae b N
Arthropoda Malacostraca Amphipoda Pleustidae c N
Arthropoda Malacostraca Amphipoda Stenothoidae a 1
Arthropoda Malacostraca Amphipoda Suborder Gammaridea c 1
Arthropoda Malacostraca Decapoda Chorilia spp. c N
Arthropoda Malacostraca Decapoda Superfamily Majoidea c 1
Arthropoda Malacostraca Decapoda Megalopae b 1
Arthropoda Malacostraca Decapoda Palaemon affinis c 1
Arthropoda Malacostraca Decapoda Pilumnus spp. c N
Arthropoda Malacostraca Decapoda Plagusia spp. c 1
Arthropoda Malacostraca Decapoda Plagusia squamosa a 1
Arthropoda Malacostraca Decapoda Planes cyaneus a, c 1
Arthropoda Malacostraca Decapoda Planes minutus a 1
Arthropoda Malacostraca Decapoda Planes spp. b, c 1
Arthropoda Malacostraca Isopoda Cirolanidae a 1
Arthropoda Malacostraca Isopoda Idotea spp. a, b, c 1
Arthropoda Malacostraca Isopoda Sphaeromatidae a 1
Arthropoda Maxillopoda Harpacticoida Harpacticoida a 1
Arthropoda Maxillopoda Kentrogonida Heterosaccus spp. c N
Arthropoda Maxillopoda Lepadiformes Barnacle cyprids a 1
Arthropoda Maxillopoda Lepadiformes Lepas anitifera a, c 1
Arthropoda Maxillopoda Lepadiformes Lepas pacifica a 1
Arthropoda Maxillopoda Lepadiformes Lepas spp. a, b, c 1
Arthropoda Maxillopoda Sessilia (Amphi)balanus amphitrite b 1
Arthropoda Maxillopoda Sessilia Chthamalus spp. c N
Arthropoda Maxillopoda Sessilia Megabalanus rosa c N
Arthropoda Pycnogonida Pantopoda Phoxichilidium
quadradentatum
a N, may encyst in
hydroids2
Arthropoda Pycnogonida Unknown Unknown c 1
Bryozoa Gymnolaemata Cheilostomatida Bugula spp. a, b, c 1
Bryozoa Gymnolaemata Cheilostomatida Jellyella eburnea a 1
Bryozoa Gymnolaemata Cheilostomatida Jellyella tuberculata a 1
Bryozoa Gymnolaemata Cheilostomatida Jellyella/Membranipora b,c 1
Bryozoa Gymnolaemata Cheilostomatida Membranipora tenella a 1
Bryozoa Gymnolaemata Ctenostomatida Bowerbankia spp. a 1
Author's personal copy
Mar Biol
1 3
Table 1 continued
Phylum Class Order Finest taxon identified Year
observed
Previously
documented as rafting
Bryozoa Gymnolaemata Ctenostomatida Victorella spp. a N, may disperse
through fragmenta-
tion of substrate3
Bryozoa Stenolaemata Cyclostomatida Filicrisia spp. a N
Bryozoa Stenolaemata Cyclostomatida Stomatopora spp. a N
Bryozoa Stenolaemata Cyclostomatida Tubulipora spp. a 1
Chordata Perciformes Actinopterygii Abudefduf spp.(vaigiensis?) b, c N/A
Chordata Perciformes Actinopterygii Canthidermis maculata c N/A
Chordata Perciformes Actinopterygii Chirolophis spp. c N/A
Chordata Perciformes Actinopterygii Coryphaena hippurus b N/A
Chordata Perciformes Actinopterygii Elagatis bipinnulata b N/A
Chordata Perciformes Actinopterygii Histrio histrio c N/A
Chordata Perciformes Actinopterygii Kyphosus spp. (vaigiensis?) b, c N/A
Chordata Perciformes Actinopterygii Meiacanthus spp. c N/A
Chordata Perciformes Actinopterygii Seriola rivoliana c N/A
Chordata Unknown Unknown Beige fish eggs c 1
Chordata Unknown Unknown Blue fish eggs c 1
Chordata Unknown Unknown Fish eggs a,b 1
Ciliophora Heterotrichea Heterotrichida Halofolliculina spp. c N on plastic, docu-
mented on wood4
Cnidaria Anthozoa Actinaria Actiniidae b 1
Cnidaria Anthozoa Actinaria Anthopleura spp. a.b N, may disperse
through detachment5
Cnidaria Anthozoa Actinaria Calliactus sp. c 7
Cnidaria Anthozoa Actinaria Metridium spp. a N, may disperse
through detachment5
Cnidaria Anthozoa Actinaria Hormathiidae c 1
Cnidaria Anthozoa Scleractinia stony coral b 1
Cnidaria Hydrozoa Leptothecata Clytia gregaria a N, though 9 other
Clytia species docu-
mented as rafting1
Cnidaria Hydrozoa Leptothecata Obelia spp. a 1
Cnidaria Hydrozoa Leptothecata Plumularia setacea a 1
Cnidaria Hydrozoa Unknown Hydroid b, c 1
Echinodermata Ophiurodea Ophiuroidea spp. 1 c
Echinodermata Ophiurodea Ophiuroidea spp. 2 c
Echinodermata Ophiurodea Ophiuroidea spp. 3 c
Foraminifera Polythalamea Rotallida Planulina ornata a N
Mollusca Bivalvia Arcoida Arcidae c N
Mollusca Bivalvia Myoida Teredo spp. c 1
Mollusca Bivalvia Myoida Zirfaea spp. (pilsbryi?) b N
Mollusca Bivalvia Mytiloida Mytilus galloprovincialis a, c 1
Mollusca Bivalvia Ostreoida Crassostrea gigas b, c 1
Mollusca Bivalvia Pectinoida Chlamys spp. c 1
Mollusca Bivalvia Pteroida Pinctada spp. c 1
Mollusca Bivalvia Unknown Lower valve of oyster c 1
Mollusca Gastropoda Caenogastropoda Litiopa melanostoma c 1
Author's personal copy
Mar Biol
1 3
Table 1 continued
Phylum Class Order Finest taxon identified Year
observed
Previously
documented as rafting
Mollusca Gastropoda Littorinimorpha Erronea spp. c N, may have
widespread larval
transport6
Mollusca Gastropoda Nudibranchia Fiona pinnata a, b, c 1
Mollusca Gastropoda Nudibranchia Fiona pinnata eggs a 1
Mollusca Gastropoda Pleurobranchomorpha Berthella spp. c N
Mollusca Gastropoda Superfamily
Pyramidelloidea
Odostomia (Evalea)
tenuisculpta
a N
Platyhelminthes Rhabditophora Polycladida Rhabditophora c 1
Platyhelminthes Rhabditophora Rhabdocoela Rhabdocoela c 1
Platyhelminthes Turbellaria Unknown Flatworm a, b 1
Platyhelminthes Turbellaria Unknown Flatworm b 1
Porifera Calcarea Leucosolenida Sycon spp. b, c N
Porifera Demospongiae Halichondrida Halichondria panacea a N
Years observed are a = Eastern Pacific 2009; b = Eastern Pacific 2011; c = Western Pacific 2012. Previously documented as rafting are
N = Not listed as rafting in the scientific literature, N/A = fishes
1 listed in Thiel and Gutow 2005b, 2 Lovely 2005, 3 Carter et al. 2010, 4 Matthews 1963, 5 Riemann-Zürneck 1998, 6 Emerson and Chaney 1995,
7 Bryan et al. 2012
Fig. 3 Characteristics of raft-
ing taxa. a Phyla found on or
around floating plastic debris.
b Feeding types of rafting taxa.
NA denotes eggs. c Mobile
taxa versus sessile taxa. Fishes
are excluded. d Taxa that have
previously been documented to
occur in rafting communities
versus taxa that have not been
documented. There was no
statistical difference between
cruise years/locations (chi-
square test, P > 0.5 for all tests)
for these analyses, so data from
all cruises were combined in
this figure. N = 95 taxa
Author's personal copy
Mar Biol
1 3
Origin of rafting organisms
Many of the rafting taxa found are known invaders, but
could have come either from their native range or from an
area in which they are already established as a non-native
species. These include the acorn barnacle Megabalanus
rosa, native to Japan but an invasive species in Australia,
and the mussel Mytilus galloprovincialis and acorn bar-
nacle Amphibalanus amphitrite, which are invasive to the
eastern Pacific (Fofonoff et al. 2012). Other taxa may have
settled onto debris in coastal areas and been transported
offshore (Astudillo et al. 2009), such as the bryozoan Vic-
torella spp., which primarily occurs in estuarine waters
(Carter et al. 2010).
Because most of the fauna present were either known
members of the North Pacific rafting assemblage or widely
distributed taxa, the source of the debris objects could not
be determined from the associated assemblage. We know
of no other reliable way to age or source plastic debris
(though see the general analysis of net type in Jacobsen
et al. 2010). Even debris with some identifying markings or
text in a particular language cannot always be attributed to
a country of origin due to the extent of international trade
and the variety of household items used on ships.
The transport of invasive species on debris originat-
ing during the March 11, 2011, Tohoku Earthquake and
subsequent tsunami event has received much attention
recently, especially regarding objects such as docks that
harbor entire communities of coastal organisms (Choong
and Calder 2013; Gewin 2013). It is possible that some
debris collected during the 2011 and 2012 expeditions orig-
inated from the Japan tsunami. However, we believe this
is unlikely, since both expeditions occurred outside of the
locations where high tsunami debris concentrations were
predicted to occur at the time of the expedition (Lebreton
and Borrero 2013).
Relationship between number of taxa and debris size
We found a greater number of taxa on larger debris items
than on smaller items. A positive relationship between
object size and taxa number has also been observed in
algal rafts (Ingólfsson 1995; Hobday 2000; Clarkin et al.
2012), fish aggregation devices (Nelson 2003), and pumice
(Bryan et al. 2012). The greater number of taxa on larger
objects could be a stochastic effect. If individuals are ran-
domly distributed over all floating objects available, then
larger objects would receive more species. However, this
relationship may also be driven by both physical and bio-
logical factors. Physically, larger objects are more likely to
remain buoyant, even after developing a substantial rafting
assemblage (Thiel and Gutow 2005a). Smaller objects with
a substantial rafting assemblage may have become nega-
tively buoyant and were therefore not sampled by this study
or by other studies focusing on material at the sea surface.
In addition, some objects were likely to have entered the
water without attached biota (e.g., a toothbrush), while
some objects were likely to have had some attached biota
at the time they were lost (e.g., an eel trap). Larger items
were primarily associated with fishing activities and may
be more likely to have a higher number of taxa due to pre-
vious attachments.
Biological interactions, as predicted by island bioge-
ography, may also be an important driver of the positive
species–area relationship on pelagic plastic debris. As
on islands, the rate of migration to large pieces of plastic
debris may exceed the rate of extinction (Simberloff 1976).
Higher rates of migration to larger objects could be driven
by larval settlement. For example, due to their greater sur-
face area, larger objects may be more likely to give off the
appropriate cues for larval settlement (Rodriguez et al.
1993). Larger objects may also be easier for fishes to detect
through visual and auditory cues (Dempster and King-
sford 2003). Furthermore, they are more stable at the sea
surface, which is an important driver of diversity (Bravo
et al. 2011; Bryan et al. 2012). Large items without spatial
stability may contain low diversity, such as a meter-long
cylindrical polystyrene buoy that “rolled” along the sea
surface (H.S.C. pers. obs.). Lastly, successional stage may
Fig. 4 Number of taxa versus surface area (m2) of debris object.
a Semilog plot. Solid line is an exponential nonlinear least squares
regression. Kendall’s tau, τ = 0.555, P < 0.001. b Log–log plot.
Solid line is a linear regression (linear regression, r2 = 0.169,
F1.66 = 48.69, P < 0.001). Symbols in both plots correspond to year
and location of collection: eastern Pacific 2009 is shown in circles,
eastern Pacific 2011 in triangles, and western Pacific 2012 in dia-
monds. Note that many of the symbols denoting small plastic objects
overlap, making the sample size hard to discern visually. N = 242
debris objects
Author's personal copy
Mar Biol
1 3
influence diversity. A study in the western Pacific found
that diversity was highest during early stages of succession
and then reduced by Lepas dominance (Tsikhon-Lukanina
et al. 2001). The authors suggested that diversity may
increase once more at later successional stages, which they
define as being dominated by bivalves. However, floating
debris in their study never reached this stage, perhaps due
to lack of physical stability or limited larval supply. A study
on algal rafts suggested that the separation and exchange of
rafting materials may affect the successional progression,
which may also apply to some marine debris (e.g., rope and
net masses) but may not apply to solid plastic objects that
are less likely to coalesce (Clarkin et al. 2012).
We have two potential explanations for the shallow para-
bolic shape of some of the taxa–area semi-log curves pre-
sented here: (1) it could be an artifact of different sampling
methodologies for medium and large objects; (2) higher
predator abundance on large objects suppresses prey diver-
sity. We cannot rule out the parabola as a sampling artifact,
because medium objects (e.g., plastic fragments) were
preserved without subsampling, while large objects (e.g.,
buoys) had to be subsampled at sea. The difference in pres-
ervation strategy could have caused inconspicuous taxa on
large objects to be undersampled. To address the sampling
issue, future studies should consider subsampling larger
items with non-selective methodology such as suction.
However, it is also possible that there is a threshold
debris size beyond which fish and decapod predators sup-
press prey taxa diversity through direct predation and/
or non-consumptive predator effects (Matassa and Trus-
sell 2011). Some epipelagic fishes preferentially associate
with fouled rafting objects as opposed to unfouled raft-
ing objects, suggesting that some of these fishes may prey
on rafting invertebrates (Nelson 2003, Thiel and Gutow
2005b), though other studies have not found significant pre-
dation on the fouling community (Ibrahim et al. 1996; Nel-
son 2003; Vassilopoulou et al. 2004). Most fishes observed
in this study were associated with the three net and rope
masses, with the exception of one juvenile triggerfish (Can-
thidermis maculata) on a bleach bottle and a school of ser-
geant majors (Abudefduf spp.) inside a plastic crate. The
net-associated fishes exhibited all three types of behavior
identified by Hirosaki (1960) for macroalgae-associated
fishes: staying almost exclusively within the net mass,
such as the sargassum frogfish (Histrio histrio); remaining
underneath or around the mass in close association, such
as the sergeants; and swimming around the mass without
close association, such as the mahi mahi (Coryphaena hip-
purus). We also observed fish entangled in net masses that
were still alive, recently dead, and partially decomposed.
The conspicuously low abundance or absence of some spe-
cies such as Lepas spp. and Halobates spp. eggs on net
masses compared with isolated fragments may be partially
attributed to these net-mass-associated fishes. For example,
the forward half of a small fishing boat floating upright in
the western Pacific had more than 50 associated individual
fish, but very little attached biota (M.E. pers. obs.).
Plastic-associated rafting organisms may also be impact-
ing the pelagic ecosystem by reworking the organic particle
size spectrum through ingestion and egestion (Mook 1981).
Suspension-feeding rafting organisms prey on a variety of
particle sizes, from 3 to 5 μm for Mytilus mussels (Lesser
et al. 1992), 10–20 μm for bryozoans (Pratt 2008), 20–
125 μm for caprellid amphipods (Caine 1977), and 0.5 to
more than 1 mm for lepadid barnacles and hydroids (Evans
1958; Boero et al. 2007; Goldstein and Goodwin 2013).
This size range encompasses much of the non-microbial
organic particle size spectrum of the oligotrophic North
Pacific (Sheldon et al. 1972). Since organic particle size
determines whether energy flows into the microbial loop
or into the metazoan food web, large-scale alterations in
particle size could substantially influence the species com-
position of the North Pacific subtropical gyre (Karl et al.
2001). Future research should also consider phytoplankton
and microbial interactions with pelagic plastic macrodebris
(Maso et al. 2003; Zettler et al. 2013; Carson et al. 2013).
Though the majority of plastic debris items in the
North Pacific are small fragments (Goldstein et al. 2013),
we found in this study that such particles carry few taxa,
most of which are known subtropical rafters such as Jel-
lyella or Membranipora bryozoans. We found the majority
of displaced taxa on large items such as net balls, though
the coral pathogen Halofolliculina spp. was found on
medium-sized plastic fragments (0.03–0.1 m2). Species
introductions from beached debris are most likely to occur
on surfaces similar to the hard raft substrate (i.e., bedrock
shorelines) and during large debris deposition events (i.e.,
storms). While debris removal operations are important
to engaging the public on marine debris issues, they are
unlikely to significantly reduce the chances of non-native
species introductions from plastic debris. This is because
coastal cleanups frequently occur on sandy beaches that
are inherently inhospitable to rafting organisms and at pre-
determined dates unlikely to coincide with major debris
deposition events. While some rapid-response operations to
large debris beachings, such as ships and docks originat-
ing from the 2011 Japanese tsunami event, may have been
effective in preventing species introductions in limited cir-
cumstances, large-scale debris cleanup on rocky, remote
shores is impracticable. Efforts to prevent debris input from
both coastal sources (e.g., urban areas) and ocean sources
(e.g., fishing debris) are likely the most efficient means of
controlling debris-mediated species introductions.
Durable plastic “islands” are hosts to a diversity of
coastal organisms in the pelagic environment, but the eco-
logical role of plastic-associated rafting assemblages on
Author's personal copy
Mar Biol
1 3
the open ocean remains unclear. Whether or not the plastic
rafts introduce new species to distant coastal regions, the
consequences of these “misplaced” organisms to open-
ocean ecosystems, especially in debris-accumulation zones,
merits further study. However, any potential impacts of the
debris-associated rafting community on coastal or pelagic
ecosystems can be most effectively limited by an overall
reduction in the quantity of plastic pollution introduced
into the marine environment.
Acknowledgments Funding for the 2009 SEAPLEX cruise was
provided by University of California Ship Funds, Project Kaisei/
Ocean Voyages Institute, AWIS-San Diego, and NSF IGERT Grant
No. 0333444. The 2011 and 2012 expeditions were made possible
through collaboration between the 5 Gyres Institute, Algalita Marine
Research Institute, and the University of Hawaii, Hilo. The Sea
Dragon was made available by Pangaea Explorations. M.C.G. was
supported by NSF GK-12 Grant No. 0841407 and donations from
Jim and Kris McMillan, Jeffrey and Marcy Krinsk, Lyn and Norman
Lear, Ellis Wyer, and the Petersen Charitable Foundation. Funding for
H.S.C. was provided by the Will J. Reid Foundation through a grant
to K. McDermid. Laboratory supplies, support, and some analytical
equipment for the 2009 samples were supplied by the SIO Pelagic
Invertebrate Collection and the California Current Ecosystem LTER
site supported by NSF. Many thanks to the captain and crew of the
R/V New Horizon and Sea Dragon for their assistance in debris
collection and many other logistics. We are grateful to H. Cha, M.
DeMaintenon, M. Forrest, E. Moore, L. Sala, A. Townsend, and J.
Winston for their assistance with taxonomy and to S. Strutt for her
work in the laboratory. Comments from L. Gutow, M.R. Landry, M.D.
Ohman, M. Thiel, and an anonymous reviewer significantly improved
this manuscript.
References
Aliani S, Molcard A (2003) Hitch-hiking on floating marine debris:
macrobenthic species in the Western Mediterranean Sea. Hydrobi-
ologia 503:59–67. doi:10.1023/B:HYDR.0000008480.95045.26
Andrady AL (2011) Microplastics in the marine environment. Mar
Pollut Bull 62:1596–1605. doi:10.1016/j.marpolbul.2011.05.030
Astudillo JC, Bravo M, Dumont CP, Thiel M (2009) Detached aquacul-
ture buoys in the SE Pacific: potential dispersal vehicles for associ-
ated organisms. Aquat Biol 5:219–231. doi:10.3354/ab00151
Barnes DKA (2002) Invasions by marine life on plastic debris. Nature
416:808–809. doi:10.1038/416808a
Barnes DKA, Fraser KPP (2003) Rafting by five phyla on man-made
flotsam in the Southern Ocean. Mar Ecol Prog Ser 262:289–291.
doi:10.3354/meps262289
Barnes DKA, Milner P (2005) Drifting plastic and its consequences
for sessile organism dispersal in the Atlantic Ocean. Mar Biol
146:815–825. doi:10.1007/s00227-004-1474-8
Barnes DKA, Galgani F, Thompson RC, Barlaz M (2009) Accumula-
tion and fragmentation of plastic debris in global environments.
Philos T Roy Soc B 364:1985–1998. doi:10.1098/rstb.2008.0205
Boero F, Bucci C, Colucci AMR et al (2007) Obelia (Cnidaria, Hydro-
zoa, Campanulariidae): a microphagous, filter-feeding medusa.
Mar Ecol 28:178–183. doi:10.1111/j.1439-0485.2007.00164.x
Bravo M, Astudillo JC, Lancellotti D et al (2011) Rafting on abi-
otic substrata: properties of floating items and their influ-
ence on community succession. Mar Ecol Prog Ser 439:1–17.
doi:10.3354/meps09344
Brown DM, Cheng L (1981) New net for sampling the ocean surface.
Mar Ecol Prog Ser 5:225–227. doi:10.3354/meps005225
Bryan SE, Cook AG, Evans JP et al (2012) Rapid, long-distance dis-
persal by pumice rafting. PLoS ONE 7:e40583. doi:10.1371/
journal.pone.0040583
Caine EA (1977) Feeding mechanisms and possible resource parti-
tioning of the Caprellidae (Crustacea: Amphipoda) from Puget
Sound, USA. Mar Biol 42:331–336. doi:10.1007/BF00402195
Carpenter EJ, Smith KL (1972) Plastics on the Sargasso Sea surface.
Science 175:1240. doi:10.1126/science.175.4027.1240
Carson HS, Nerheim MS, Carroll KA, Eriksen M (2013) The plastic-
associated microorganisms of the North Pacific Gyre. Mar Pollut
Bull 75:126–132. doi:10.1016/j.marpolbul.2013.07.054
Carter MC, Bishop JDD, Evans NJ, Wood CA (2010) Environmen-
tal influences on the formation and germination of hibernacula in
the brackish-water bryozoan Victorella pavida Saville Kent, 1870
(Ctenostomata: Victorellidae). J Exp Mar Biol Ecol 383:89–95.
doi:10.1016/j.jembe.2009.11.012
Choong HHC, Calder DR (2013) Sertularella mutsuensis Stechow,
1931 (Cnidaria: Hydrozoa: Sertulariidae) from Japanese tsu-
nami debris: systematics and evidence for transoceanic dispersal.
BioInvasions Rec 2:33–38
Clarkin E, Maggs CA, Allcock AL, Johnson MP (2012) Environment,
not characteristics of individual algal rafts, affects composition of
rafting invertebrate assemblages in Irish coastal waters. Mar Ecol
Prog Ser 470:31–40
Croquer A, Bastidas Carolina, Lipscomb D (2006) Folliculinid cili-
ates: a new threat to Caribbean corals? Dis Aquat Org 69:75–78.
doi:10.3354/dao069075
Dameron OJ, Parke M, Albins MA, Brainard R (2007) Marine debris
accumulation in the Northwestern Hawaiian Islands: an exami-
nation of rates and processes. Mar Pollut Bull 54:423–433.
doi:10.1016/j.marpolbul.2006.11.019
Davidson TM (2012) Boring crustaceans damage polystyrene floats
under docks polluting marine waters with microplastic. Mar Pol-
lut Bull 64:1821–1828. doi:10.1016/j.marpolbul.2012.06.005
Dempster T, Kingsford M (2003) Homing of pelagic fish to fish
aggregation devices (FADs): the role of sensory cues. Mar Ecol
Prog Ser 258:213–222. doi:10.3354/meps258213
Derraik JGB (2002) The pollution of the marine environment by plas-
tic debris: a review. Mar Pollut Bull 44:842–852. doi:10.1016/
S0025-326X(02)00220-5
Development Core Team R (2012) R: a language and environment for
statistical computing. Austria, Vienna
Donlan CJ, Nelson PA (2003) Observations of invertebrate colonized
flotsam in the eastern tropical Pacific, with a discussion of raft-
ing. B Mar Sci 72:231–240
Emerson W, Chaney H (1995) A zoogeographic review of the
Cypraeidae (Mollusca, Gastropoda) occurring in the eastern
Pacific Ocean. Veliger 38:8–21
Evans F (1958) Growth and maturity of the barnacles Lepas hillii
and Lepas anatifera. Nature 182:1245–1246. doi:10.1038/
1821245b0
Farrapeira CMR (2011) Invertebrados macrobentônicos detectados na
costa brasileira transportados por resíduos flutuantes sólidos abi-
ogênicos. Revista da Gestão Costeira Integrada 11:85–96
Fofonoff P, Ruiz G, Steves B, Carlton J (2012) National Exotic
Marine and Estuarine Species Information System. In: Smithso-
nian Environmental Research Center. http://invasions.si.edu/nem-
esis/. Accessed 26 Oct 2012
Gewin V (2013) Tsunami triggers invasion concerns. Nature 495:13–
14. doi:10.1038/495013a
Godwin LS, Harris L, Charette A, Moffitt R (2008) The marine inver-
tebrate species associated with the biofouling of derelict fishing
gear in the Pa¯pahanaumokua¯ kea–Marine National Monument: a
focus on marine non-native species transport. p 26
Author's personal copy
Mar Biol
1 3
Goldstein MC, Goodwin DS (2013) Gooseneck barnacles (Lepas
spp.) ingest microplastic debris in the North Pacific Subtropical
Gyre. PeerJ 1:184. doi:10.7717/peerj.184
Goldstein MC, Rosenberg M, Cheng L (2012) Increased oceanic
microplastic debris enhances oviposition in an endemic pelagic
insect. Biol Lett 8:817–820. doi:10.1098/rsbl.2012.0298
Goldstein MC, Titmus AJ, Ford M (2013) Scales of spatial heteroge-
neity of plastic marine debris in the northeast Pacific ocean. PLoS
ONE 8:e80020. doi:10.1371/journal.pone.0080020
Hammer J, Kraak HS Michiel, Parsons John R (2012) Plastics in the
marine environment: the dark side of a modern gift. Rev Environ
Contam T 220:1–44. doi:10.1007/978-1-4614-3414-6_1
He F, Legendre P (1996) On species-area relations. Am Nat
148:719–737
Hidalgo-Ruz V, Gutow L, Thompson RC, Thiel M (2012) Microplas-
tics in the marine environment: a review of the methods used for
identification and quantification. Environ Sci Technol 46:3060–
3075. doi:10.1021/es2031505
Hirosaki Y (1960) Observations and experiments on the behavior of
fishes toward floating objects in aquarium. J Fac Sci Hokkaido
Univ 14:320–326
Hobday AJ (2000) Persistence and transport of fauna on drifting
kelp (Macrocystis pyrifera (L.) C. Agardh) rafts in the Southern
California Bight. J Exp Mar Biol Ecol 253:75–96. doi:10.1016/
S0022-0981(00)00250-1
Hoeksema BW, Roos PJ, Cadee GC (2012) Trans-Atlantic rafting by
the brooding reef coral Favia fragum on man-made flotsam. Mar
Ecol Prog Ser 445:209–218. doi:10.3354/meps09460
Ibrahim S, Ambak MA, Shamsudin L, Samsudin MZ (1996)
Importance of fish aggregating devices (FADs) as sub-
strates for food organisms of fish. Fish Res 27:265–273.
doi:10.1016/0165-7836(96)00473-0
Ingólfsson A (1995) Floating clumps of seaweed around Iceland: nat-
ural microcosms and a means of dispersal for shore fauna. Mar
Biol 122:13–21. doi:10.1007/BF00349273
Jacobsen JK, Massey L, Gulland F (2010) Fatal ingestion of floating
net debris by two sperm whales (Physeter macrocephalus). Mar
Pollut Bull 60:765–767. doi:10.1016/j.marpolbul.2010.03.008
Karl DM, Bidigare RR, Letelier RM (2001) Long-term changes in
plankton community structure and productivity in the North
Pacific Subtropical Gyre: the domain shift hypothesis. Deep Sea
Res Pt II 48:1449–1470. doi:10.1016/S0967-0645(00)00149-1
Law KL, Moret-Ferguson S, Maximenko NA et al (2010) Plastic
accumulation in the North Atlantic Subtropical Gyre. Science
329:1185–1188. doi:10.1126/science.1192321
Lebreton LC-M, Borrero JC (2013) Modeling the trans-
port and accumulation floating debris generated by the 11
March 2011 Tohoku tsunami. Mar Pollut Bull 66:53–58.
doi:10.1016/j.marpolbul.2012.11.013
Lesser MP, Shumway SE, Cucci T, Smith J (1992) Impact of foul-
ing organisms on mussel rope culture: interspecific competition
for food among suspension-feeding invertebrates. J Exp Mar Biol
Ecol 165:91–102. doi:10.1016/0022-0981(92)90291-H
Lomolino MV (2000) Ecology’s most general, yet protean pattern: the
species-area relationship. J Biogeogr 27:17–26
Lovely EC (2005) The life history of Phoxichilidium tubulariae
(Pycnogonida: Phoxichilidiidae). Northeastern Nat 12:77–92.
doi:10.1656/1092-6194(2005)012[0077:TLHOPT]2.0.CO;2
MacArthur RH, Wilson EO (1963) An equilibrium theory of insular
zoogeography. Evolution 17:373–387
Majer AP, Vedolin MC, Turra A (2012) Plastic pellets as oviposition site
and means of dispersal for the ocean-skater insect Halobates. Mar
Pollut Bull 64:1143–1147. doi:10.1016/j.marpolbul.2012.03.029
Maso M, Garces E, Pages F, Camp J (2003) Drifting plastic debris as
a potential vector for dispersing harmful algal bloom (HAB) spe-
cies. Sci Mar 67:107–111
Matassa CM, Trussell GC (2011) Landscape of fear influences the
relative importance of consumptive and nonconsumptive predator
effects. Ecology 92:2258–2266. doi:10.1890/11-0424.1
Matthews DC (1963) Hawaiian records of folliculinids (Protozoa)
from submerged wood. Pac Sci 17:438–443
McDermid KJ, McMullen TL (2004) Quantitative analysis of small-
plastic debris on beaches in the Hawaiian archipelago. Mar Pollut
Bull 48:790–794
Mook DH (1981) Removal of suspended particles by fouling commu-
nities. Mar Ecol Prog Ser 5:279–281
Moret-Ferguson S, Law KL, Proskurowski G et al (2010) The size,
mass, and composition of plastic debris in the western North Atlan-
tic Ocean. Mar Pollut Bull 60:1873–1878. doi:10.1016/j.marpolbul.
2010.07.020
Nelson PA (2003) Marine fish assemblages associated with fish aggre-
gating devices (FADs): effects of fish removal, FAD size, fouling
communities, and prior recruits. Fish B-NOAA 101:835–850
Palmer C, Gates R (2010) Skeletal eroding band in Hawaiian corals.
Coral Reefs 29:469. doi:10.1007/s00338-010-0597-2
Pham PH, Jung J, Lumsden JS et al (2012) The potential of waste items
in aquatic environments to act as fomites for viral haemorrhagic
septicaemia virus. J Fish Dis 35:73–77. doi:10.1111/j.1365-2761.
2011.01323.x
Pister B (2009) Urban marine ecology in southern California: the
ability of riprap structures to serve as rocky intertidal habitat.
Mar Biol 156:861–873. doi:10.1007/s00227-009-1130-4
Pratt MC (2008) Living where the flow is right: how flow affects feed-
ing in bryozoans. Integr Comp Biol 48:808–822. doi:10.1093/icb/
icn052
Rasband WS (2012) ImageJ. U. S. National Institutes of Health,
Bethesda MD. http://imagej.nih.gov/ij/
Riemann-Zürneck K (1998) How sessile are sea anemones? A review
of free-living forms in the Actiniaria (Cnidaria: Anthozoa). Mar
Ecol 19:247–261. doi:10.1111/j.1439-0485.1998.tb00466.x
Rodriguez SR, Ojeda FP, Inestrosa NC (1993) Settlement of benthic
marine invertebrates. Mar Ecol Prog Ser 97:193–207
Rodriguez S, Cróquer A, Guzmán H, Bastidas C (2009) A mecha-
nism of transmission and factors affecting coral susceptibility to
Halofolliculina sp. infection. Coral Reefs 28:67–77. doi:10.1007/
s00338-008-0419-y
Ryan PG (2013) A simple technique for counting marine debris at sea
reveals steep litter gradients between the Straits of Malacca and
the Bay of Bengal. Mar Pollut Bull 69:128–136. doi:10.1016/
j.marpolbul.2013.01.016
Sheldon RW, Prakash A, Sutcliffe WH (1972) The size distribution of
particles in the ocean. Limnol Oceangr 17:327–340
Simberloff D (1976) Experimental zoogeography of islands: effects of
island size. Ecology 57:629–648
Thiel M, Gutow L (2005a) The ecology of rafting in the marine envi-
ronment I: the floating substrata. Oceanogr Mar Biol 42:181–263
Thiel M, Gutow L (2005b) The ecology of rafting in the marine envi-
ronment II: the rafting organisms and community. Oceanogr Mar
Biol 43:279–418
Thiel M, Haye PA (2006) The ecology of rafting in the marine envi-
ronment III: biogeographical and evolutionary consequences.
Oceanogr Mar Biol 44:323–429
Titmus AJ, Hyrenbach KD (2011) Habitat associations of float-
ing debris and marine birds in the North East Pacific Ocean at
coarse and meso spatial scales. Mar Pollut Bull 62:2496–2506.
doi:10.1016/j.marpolbul.2011.08.007
Tsikhon-Lukanina EA, Reznichenko OG, Nikolaeva GG (2001) Ecol-
ogy of invertebrates on the oceanic floating substrata in the north-
west Pacific ocean. Oceanology 41:525–530
Tyrrell MC, Byers JE (2007) Do artificial substrates favor nonindig-
enous fouling species over native species? J Exp Mar Biol Ecol
342:54–60
Author's personal copy
Mar Biol
1 3
U.S. Environmental Protection Agency (2011) Marine Debris in the
North Pacific: A summary of existing information and identifica-
tion of data gaps. p 23
Vassilopoulou V, Siapatis A, Christides G, Bekas P (2004) The biol-
ogy and ecology of juvenile pilotfish (Naucrates ductor) associ-
ated with fish aggregating devices (FADs) in eastern Mediterra-
nean waters. Mediterr Mar Sci 5:61–70. doi:10.12681/mms.211
Venrick EL, Backman TW, Bartram WC et al (1973) Man-made
objects on the surface of the central North Pacific Ocean. Nature
241:271. doi:10.1038/241271a0
Whitehead TO, Biccard A, Griffiths CL (2011) South African pelagic
goose barnacles (Cirripedia, Thoracica): substratum preferences
and influence of plastic debris on abundance and distribution.
Crustaceana 84:635–649. doi:10.1163/001121611X574290
Winston JE, Gregory MR, Stevens L (1997) Encrusters, epibionts, and
other biota associated with pelagic plastics: a review of biologi-
cal, environmental, and conservation issues. In: Coe JM, Rogers
DB (eds) Marine debris: sources, impact and solutions. Springer,
New York, pp 81–98
Wong CS, Green DR, Cretney WJ (1974) Quantitative tar and plastic
waste distributions in Pacific Ocean. Nature 247:30–32. doi:10.1038/
247030a0
Ye S, Andrady AL (1991) Fouling of floating plastic debris under
Biscayne Bay exposure conditions. Mar Pollut Bull 22:608–613.
doi:10.1016/0025-326X(91)90249-R
Zettler ER, Mincer TJ, Amaral-Zettler LA (2013) Life in the “Plasti-
sphere”: microbial communities on plastic marine debris. Envi-
ron Sci Technol 47:7137–7146. doi:10.1021/es401288x
Author's personal copy
