ArticlePDF Available

Population expansion of a new invasive coral species, Tubastraea micranthus, in the northern Gulf of Mexico

Authors:

Abstract and Figures

An Indo-Pacific scleractinian coral has invaded the northern Gulf of Mexico (GOM): Tubastraea micranthus. It was initially observed on one oil platform (GI-93C) near the Mississippi River. Here, we determined whether its populations were spreading and whether there was evidence of rapid expansion. We compared population density data of T. micranthus with those from T. coccinea, a congener which invaded the western Atlantic earlier. Fourteen oil/gas platforms were assessed down to 138 m depth using remotely operated vehicle digital video. Colony den sities in numbers m(-2) were determined for both species, and colony size was measured for T. micranthus. Data were analyzed by platform and for geographic distribution. T. micranthus densities were highest on GI-93C and on GI-116A, SW of the Mississippi River, being significantly higher than on other platforms. Densities declined radially from there. Mean colony size was highest on MC-311A, with colonies generally being > 100 cm(2). This platform is situated at the head of the Mississippi Canyon and may have been the original site of colonization. It also receives blue water instead of turbid, lower salinity water, and this species may grow better under those conditions. T. micranthus size frequency distributions were generally skewed towards 1-200 cm(2) (5 cm diameter) (sometimes > 90% of the population), suggesting that most populations are potentially in an expanding growth phase. T. coccinea densities were high (range: similar to 50 to 300 colonies m(-2)). Its populations were also centered SW of the Mississippi River. T. micranthus is spreading through this region, and the window for its potential eradication may be closing.
Content may be subject to copyright.
Population Expansion of a New Invasive Coral Species - Tubastraea micranthus -
in the northern Gulf of Mexico
by
Paul W. Sammarco1,2, Scott A. Porter1,3, James Sinclair4, and Melissa Genazzio1,5.
1Louisiana Universities Marine Consortium (LUMCON)
8124 Hwy. 56
Chauvin, LA 70344
USA
psammarco@lumcon.edu
2Department of Oceanography and Coastal Sciences
Louisiana State University
Baton rouge, LA 70803
USA
3Ecologic Environmental, Inc.
PO 886
Houma, LA 70361
USA
4US Department of the Interior
Bureau of Safety and Environmental Enforcement (BSEE)
1201 Elmwood Park Blvd.
New Orleans, LA 70123-2394, USA
5Center for Marine Science
University of North Carolina at Wilmington
601 S. College Rd.
Wilmington, NC 28403-5928, USA
Running Head: Distribution and Abundance of Tubastraea micranthus
Keywords: Coral, invasive species, Tubastraea micranthus, Gulf of Mexico, spread, oil
platforms
1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
1
2
Abstract
An new Indo-Pacific scleractinian coral has invaded the northern Gulf of Mexico (GOM)
Tubastraea micranthus. It was initially observed on one oil platform (GI-93C) near the
Mississippi River. Here wWe determined whether its populations were spreading throughout the
region and whether there was evidence of rapid population expansion. We also compared
population density data with those fromat of T. coccinea, a congeneric species which
successfully invaded the western Atlantic earlier. Fourteen oil/gas platforms were assessed
down to 138 m depth (max.) using by remotely operated vehicle (ROV), digital video. Densities
in no./m2 were determined for both species, and colony size for T. micranthus. Data were
analyzed by platform and for also with respect to geographic distribution. T. micranthus
densities were highest on GI-93C and on GI-116A, SW of the Mississippi River, being
significantly higher than most other platformsinflux of recruitments. Densities declined radially
from there, suggesting this to be the epicenter of colonization. Mean colony size was highest on
MC-311A, t all colonies generally surveyed being larer than area. This platfs at the head of the
Mississippi Canyon andn, characterized by blue water instead of the turbid, lower salinity water
of other sites. This suggests that so receives blue water instead of turbid, lower salinity water,
and this speciesAlso, and /or that T. micranthus may grow betterst under blue-water conditions.
T. micranthus sSize frequency distributions of colonies for T. micranthus were generally skewed
towards 1-200 cm2 (5 cm diam.) (– sometimes >90% of the population), suggestiindicating that
most populations are potentially in an expanding explosive growth phase. T. coccinea densities
were high (range: ~50-300/m2). Its populations were also centered SW of the Mississippi River.
2
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
3
4
T. micranthus is spreading through this region and the window for its potential eradication may
be rapidly closing.
3
67
68
5
6
Introduction
Species introductions can result in major impacts on the ecosystems (Roberts and Pullin, 2008).
This is particularly so in the marine environment, because of the ease with which their
reproductive propagules can disperse and colonize nearby habitats once they have established a
new population (Griffiths, 1991; Johnson and Carlton, 1996; Wonham et al., 2000). Examples of
rapid dispersal of introduced marine species are numerous and iInclude ude marine algae
(Chapman et al., 2006), such as Codium fragile – a Japanese cholorophyte introduced apparently
via the ballast water of ships (Trowbridge, 1998; Pederson, 2000; Williams, 2007). This species
is now common throughout much of the western Atlantic (Chapman, 1999). Another example is
Caulerpa taxifolia which was accidentally released into the Mediterranean Sea from a public
aquarium in Monaco (Williams and Smith, 2007) and is now common there. This species is now
common throughout much of the western Atlantic (Chapman, 1999). Another more recent
example is the Indo-Pacific volitan lionfish (Pterois volitans). This species was most likely
released into western Atlantic waters approximately ~10 yrs ago (Whitfield et al., 2002; Hamner
et al., 2007) and is now distributed from New York, USA south through the Caribbean and South
America (Albins and Hixon, 2011). There are hundreds to thousands of such examples of
introductions from various seas, which are reviewed in, e.g., Bax et al., (2003), Womersley
(2003; Australian algae), Zenetos et al. (2005; Mediterranean fauna), etc.
Vectors for the transport of invasive marine or freshwater species (Kerr et al., 2005)
include the ballast water of barges orf ships (Chesapeake Bay Commission, 1995; ICES,
2002), the hulls of the same (Minchin and Gollasch, 2003), transfer via towing of oil and gas
4
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
7
8
platforms to new sites (Hicks and Tunnell, 1993), accidental release of exotic species from
mariculture operations (Sapota, 2004), and deliberate release of exotics by aquarium
hobbyists (Weidema, 2000; Christmas et al., 2001; Hindar et al., 2006).
Recently there has been concern regarding invasive marine species has focused onabout
sthose pecies occurring in which have invaded the Gulf of Mexico (GOM) (Osman and
Shirley, 2007). This includes the Australian scyphozoan Phyllorhiza which colonized thise
region within the past 15 yrs (Perry and Graham, 2000), and has the ability to suppress seasonal
zooplankton populations (Graham et al., 2003; Graham and Bayha, 2008) important for
commercial fisheries. Another is the zebra mussel Dreissena polymorpha, which was originally
introduced to the Great Lakes in the mid-1980s and has since spread south through North
America (Baker et al., 2006; Dextrase and Mandrak, 2006; Ram and Pallazola, 2008) all the way
to the Mississippi River mouth (Anon., 1997; Liffman, 1997).
There have been Vvery few corals have successfully invaded thesions of corals to the Atlantic.
The Indo-Pacific mushroom coral Fungia scutaria was accidentally introduced intoto Discovery
Bay, Jamaica, W.I. (J. Lang, pers. comm.; P.W. Sammarco, pers. obs., 1973; Lajeunesse et al.,
2005). (The corals were held in running seawater tables for several years, and it is hypothesized
that, during the spawning seasons, planulae were released into the water and flushed into the
lagoon through the seawater discharge drain.) The Indo-Pacific sun coral, Tubastraea coccinea
(Cairns and Zibrowius, 1997) species was first introduced into Puerto Rico in 1943, and by 1948
had spread to Curacao, Netherlands Antilles (Cairns, 2000). By the late 1990s and mid 2000s,
5
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
9
10
thise species had spread to Belize and Mexico (Fenner, 1999); Venezuela, northern Gulf of
Mexico, and the Florida Keys (Fenner, 2001; Fenner and Banks, 2004; Sammarco et al., 2004;
Shearer, 2005); Brazil (Figueira de Paula and Creed, 2004); Colombia, Panama, the Bahamas,
and throughout the Lesser and Greater Antilles (Cairns, 2000; Humann and Deloach, 2002).
Tubastraea coccinea has also been observed since ---- [what year?] on deep-water [how many
meters debanks occurring at the edge of the continental shelf of the GOM. This species is now
abundant in the northern Gulf of Mexico on artificial substrata (Sammarco et al. 2004, 2007a,b,
2012a). It is present on oil/gas platforms in abundances of hundreds of thousands of colonies per
platform, with average densities reaching from 28/m2 to 300/m2. It also occurs on deep
narbonate bBanks [be more specific – are thormed o calcium caronate in the northern Gulf of
Mexico but in lower abundances (Schmahl, 2003; Hickerson et al., 2006; Schmahl and
Hickerson, 2006). It is possible that this introduction was due to a ship, barge, or ballast water,
although the details are not known. It is also possible that the oil and gas platforms, abundant in
the northern Gulf of Mexico, have acted as stepping stones for the geographic expansion of this
species in this region (Sammarco et al., 2004; Atchison, 2005; Atchison et al., 2008; Sammarco
et al., 2012a,b). It should be noted, however, that such a geographic spread was achieved
throughout most of the western Atlantic without these structures; that is, such structures were
sufficient but not necessary for the spread of this species. [add brief text on how Tubastrea were
likely introduced t
From 2000 to 2010, Sammarco et al. (2004, 2007a,b, 2008, 2012a) and SAPPorter (unpub. data)
conducted surveys via SCUBA and remotely operated vehicle (ROV) on the distribution and
abundance of scleractinian corals on 81 oil and gas platforms - in both shallow and deep water
6
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
11
12
throughout the northern Gulf of Mexico. Surveys were conducted instretched from the offshore
waters spanningoff Corpus Christi, Texas to those off Mobile, Alabama. In his surveys, SAPPorter
found a new invasive species for the Gulf of Mexico – the Indo-Pacific black sun coral species-
Tubastraea micranthus Cairns and Zibrowius 1997 (Sammarco et al., 2010) - a closely related
congener of Tubastraea coccinea. It was initially observed in 2006 on a single platform - GI-93-C
(28o32.96’N, 90o40.11’W; Fig. 1). This was , occurring near the crossing of two major safety
fairways/shipping channels southwest of the Port of New Orleans, Louisiana, near the mouth of the
Mississippi River and Port Fourchon, Louisiana.
Once a population of a new invasive species becomes established, its spread can be broad and
rapid, greatly confounding any attempt to control or eradicate it (Elton, 2000). Examples include
the invasion of the fire ant (Solenopsis invicta) into the United States (Buhs, 2004). It was
accidentally introduced into Mobile, Alabama during the 1940s and is now distributed around the
margins of the USA from the state of Washington to New Jersey, extending approximately 800
km inland. Another example is the South American coastal herbivore Nutria (Myocastor
coypus), 20 individuals of which were introduced into Avery Island, Louisiana during the
1930’s. Its populations are now distributed from Delaware to Texas, USA and reach to inland
mid-eastern states as well as those of the northwest.
An understanding of Tubastraea coccinea’s life history traits will assist in understanding some
of the potential which T. micranthus has for geographic expansion in the GOM, and allow
comparisons between the two species. T. coccinea generally has colony sizes no larger than 25
7
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
13
14
cm in diameter in the GOM, at which point it extends runners horizontally to form new ramets.
Its growth form in the Atlantic is branching but with a low profile, to a maximum of 12-15 cm.
The polyps are red or orange in color, and the corals are ahermatypic and azooxanthellate. Their
natural habitat on Indo-Pacific reefs is cryptic, and this same habitat is adopted on natural reefs
in the western Atlantic. On artificial substrata, however, the colonies are much more exposed.
With respect to T. micranthus, colony sizes are somewhat smaller (15 cm in diameter) in the
GOM. The colonies also distribute runners to form new ramets. It is also branching in habit, but
its polyps extend to a greater extent vertically, and branch as well, making the colonies often a
bit taller (up to ~ 20 cm high; Sammarco et al., 2010; Cairns, 2000). They are dark green or
black in color and are also ahermatypic and azooxanthellate. Their natural habitat on Indo-
Pacific reefs is exposed. It is not yet known what their habit will be on natural reefs in the GOM,
although they are generally exposed on oil and gas platforms there. T. micranthus’ ability to
grow well in highly exposed habitats is reason for concern, since preliminary data indicate that
this species has a strong advantage in competition for space against other sessile, benthic
epifauna (Sammarco et al., 2012c,d).
Regarding reproduction, Tubastraea coccinea exhibited a similar broad range extension since it
was introduced in the 1940s. It is not yet known whether Tubastraea micranthus exhibits the
same population growth characteristics as its congener. Tubastraea coccinea is a single species
with a circum-tropical distribution (Cairns, 2001). It is a hermaphroditic brooder and reproduces
by producing planulae year-round (Glynn et al., 2008a). Egg development requires 6-8 wks. T.
coccinea exhibits asexual reproduction using budding, simple colony growth, and asexual
planula production (Ayre and Resing, 1986; Shearer, 2008) and runner production (Pagad, 2007).
8
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
15
16
It is considered to be a high-fecundity species and also uses sexual reproduction, producesing
gametes all year-round, even in the smallest colonies (2-10 polyps; Glynn et al., 2008a,b).
Planulae may be produced sexually or asexually (Ayre and Resing, 1986). The planular
development period is 6 wks, and the planulae settle and metamorphose within 3 days. Planular
release occurs 3-4 times per year (Hebbinghaus, 2001) from March through July, and this species
isindividuals areit is considered to possess substantialbe highly fecund (Glynn et al., 2008a,b),
with. Iformidable ts larval dispersal capabilities are formidable (Sammarco, 2012b). It is known
to withstand a variety of environmental conditions thy in othcoral species.
With respect to Tubastraea micranthus, tIf the details of its reproductionive, and dispersal
capabilities, time from release to settlement for planulae, and any obligate period that the planula
must remain in the water column prior to settlement of T. micranthus are ot yet known[?].
butwever, they are similar to those of T. coccinea, then T. micranthus former could reach
similarly high abundances similar to its congener in the western Atlantic (Sammarco et al., 2004;
Shearer, 2008). As such,That is, it is possible that there could be species could pose a potential
threat viathroua bantial massive geographic expansion of this species throughout the GOMulf
and the tropical and sub-tropical western Atlantic is poover the next 20-40 yrs.
T
The objectives of this study were to quantify the abundance of Tubastraea micranthus aton the
presumed initial introduction site of observation (Platform GI-93-C, see above); and to conduct
surveys on 13 other platforms in the vicinity of GI-93-C, extending to the bottom, of the
9
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
17
18
platforms, to determine whether its populations are expanding. We also assessed the direction in
which the expansion is occurring, in what types of environments it occurs, and to what degree.
Depth distribution information and competition-for-space capabilities of this species will be
considered elsewhere.
Materials and Methods
Study Site
The study sitesplatforms were Platform GI-93-C and 13 other platforms surrounding it within a 20
km radius (Fig. 1; Table 1). Specific platforms were chosen in consultation with the US Dept. of
the Interior - Bureau of Ocean Energy Management (BOEM). Choices were based on age and
location of the structures and availability with respect to the platform owners. . Surveys were
performed using the M/V Fling (33 m, Gulf Diving, Inc., Freeport, TX) and the R/V Acadiana (18
m, LUMCON). The study was conducted over two years, utilizing 12 days of ship-time.
TWe spent approximately two-thirds of one day were required to surveying each platform using an
ROV.
We used LUMCON’s Deep Ocean Engineering Phantom S2 ROV, which has 333 m of umbilical
and is capable of surveying down to 170 m depth. We employed the techniques previously used
successfully in earlier similar surveys (Sammarco et al., 2010, 2012a). ARACAR’s SeaBotix
LBV-300 and BOEM’s similar ROV were also used as back-ups when the primary ROV
required maintenance. All units were fitted with vertical and horizontal propulsion units, site-to-
surface color video units, a topside monitor, lights, laser beams providing a spatial scale
10
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
19
20
reference, and a sample retrieval unit (fixed grab). Length of transects varied between 18m for
horizontal struts and 170 m for the deepest vertical piling. Number of transects varied between
four and seven per platform, depending upon size of the platform. Transects consisted of two to
six horizontal transects at approximately 15-18, 23-27, and ~180 m depth respectively; the
remainder of the transects were vertical. Approximately 125-585 sq m of substratum were
surveyed on each platform, depending upon the size of the platform (number of primary pilings),
depth, time available at each platform, and weather and sea conditions. We filmed continuously
down each leg and only on the outward-facing surfaces. The side of the platform sampled was
always down-current so as to insure that the ROV and/or its umbilical was not drawn into the
interior of the structure, to reduce the probability of it becoming fouled (see Sammarco et al., in
press).
Imagery was processed using a Dell Precision 340 and T3400 desktop computers with a Pentium
4 processor and a Dell Precision M4300 Workstation fitted with a duo-core processor and
MicroSoft video imaging software. Image analysis software included Nero 7.0, VideoLAN, and
MicroSoft Windows Media Player, capable of zoom and still-image capture. Images were
analyzed at each 3 m interval within a video transect. The number of quadrats analyzed per
platform was 12-174 quadrats,, depending upon platform size and depth (see Table 1).
11
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
21
22
Data were collected for both Tubastraea micranthus and T. coccinea for comparative purposes.
In the case of T. coccinea, population densities were so high (up to hundreds per still image)
that counts were estimated visually using a log5 code system (0=1, 1=5, 2=25, 3=125, etc.),
similar to that used in the field by Williams (1982) and Halford et al. (2004) for reef fish
counts. Two laser dots of known inter-dot distance (8-12 cm, depending upon the vehicle)
within the video field of view were used to standardize for both coral density (no. corals per
unit area) and coral colony size. A transparent 10 x 10 2.54 cm grid ([total grid ara = 25.4
cm x 25.4 cm)? was this als was placed over the computer screen to assist sampling and
taking measurements. Mean densities of corals were calculated for each platform along with
standard deviations and 95% confidence limits. [range of tota
Colony size was measured for all Tubastraea micranthus colonies. . Similar data are not
presented for T. coccinea, because T. micranthus was the target organism for the study and the
objective of this study is to attempt to discern characteristics of initial population changes in the
region. It is known that T. coccinea populations are well-established in the region (Sammarco,
2012a). Colonies were assumed to be elliptical in shape, and measurements were made of the
major and minor axes. Estimated area was calculated as A = π x r1 x r2, where r1 and r2 are the
major and minor radii, respectively. Mean coral colony size was calculated for each platform
along with standard deviations and 95% confidence limits. Size-frequency diagrams were
constructed for Tubastraea micranthus colonies on each of the platforms, based on all quadrats
analyzed per platform.
Data Analysis
12
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
23
24
All quantitative data were logged in EXCEL files and stored on the primary workstation. Data
were backed-up on a 250G Western Digital G-Book external hard-drive and , updated daily as
well as on the LUMCON computer network (, which is updated continuously).
Coral density data were analyzed by parametric tests. Analyses included ANOVA and a
posteriori Multiple Comparison Tests between Means – T-K, GT-2, and T’ tests. Basic statistics
(mean, s.d., n, range, g1 – skewness, and g2 – kurtosis) were calculated for colony size frequency
distributions. Analyses were performed using BiomStat 3.2 and 3.3 (Rohlf and Slice, 1996).
Where necessary, data were transformed by square root of (Y+ 0.5) for normalization purposes
(see Sokal and Rohlf, 1981).
Two-dimensional graphics were performed using SigmaPlot 10.0. Some data are presented
within a geographic context in three dimensions, and these were constructed using SURFER 8.0
(Golden Software, 2002). Data consisted of latitudes, longitudes, and the variate in question.
Averages were determined by kriging, a geostatisical gridding method designed for use with
irregularly spaced data, using a smoothing interpolator. We used pPoint kKriging, estimating
interpolated values of points at grid nodes and a default linear variogram without a nugget effect.
Additional details may be found in Golden Software (2002).
Results
Tubastraea micranthus
Data derived from analysis of ROV videos revealed that Tubastraea micranthus’ populations had
were indeed distributed outside of spread from GI-93-C on other to surrounding platforms in the
13
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
25
26
study area. Out of 14 platforms surveyed, this species was found on 9, including GI-93-C (Fig.
2). In addition, density data was highest on this platform of initial sighting, averaging
approximately 15/m2. This suggests that this site may well have been the site of original
colonizationexperienced substantial colonization from elsewhere. The platforms did not possess
the same densities of corals. ANOVAs and subsequent a posteriori tests revealed that densities
on GI-93C were significantly higher than on all other platforms except GI-116-A116A (Table
2a), which was not significantly different than GI-93C. Details regarding inter-platform
comparisons may be found in Table 2a. T. micranthus did not occur on Platforms ST-185-
A185A & B, GI-94-B, ST-81-A81A, and ST-75JA(B) (Fig. 2).
When density data were placed into a geographic context, it could be seen that Tthe peak density
of T. micranthus occurred to the southwest of the mouth of the Mississippi River (Fig. 3), next to
two major safety fairways servicing the Port of New Orleans and the Port Fourchon (Sammarco
et al., 2010). A second somewhat smaller peak in density occurredcould be seen south of GI-93-
C. This suggests that the introduction of this species may have been derived from larvae being
released from a passing ship or barge. In general, densities fell off in all directions in near
proximity to these points, with a minor peak west-southwest of the Mississippi River mouth.
Densities roseThere was a moderately rise in densities to the east of the Mississippi River.
Patterns of average colony size for Tubastraeaa. micranthus did not follow that of average
density. MThe maximum average colony size was found on Platform MC-311-A311A (Fig. 4)
and. It was significantly higher than on all other platforms (see Table 2b3 for pair-wise inter-
platform comparisons). The next largest average T. micranthus colony size was found on MC-
14
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
27
28
109A (mean = 198.6 cm2, s = 281.14, n = 47, range = 1.2 – 1,204 cm2
) , and it was significantly
higher than the average colony size on SP-87D, GI-116-A, and GI-93C. Average colony size on
almost all other platforms did was equivalent (not significantly different)other (, except on GI-
115A) versus ST-206A, and GI-93C versus SP-87-D. When these differences are placed into a
geographical context, the [obvionthree-dimensional representation of average colony size
demonstrates that colony size not only peakeds at MC-311-A311A, but it also droppeds off
evenly from that point in all directions, with no secondary peaks in that region (Fig. 5).
Size-frequency diagrams were constructed for Tubastraea micranthus colonies on each of the
platforms. Size-frequency distributions of T. micranthus revealed that onIn the case of Platform
MC-109-A109A, , it could be seen that a large proportion of the colonies ( - ~60%) - were
between one and 100 cm2 in area (max. diameter = ~11 cm, ) in area (Fig. 6). CFrequencies of
smaller [larger??] average colony size category sizeies? dDecreased ifell off rapidly after this s.
nclear-sate.] This pattern of a logarithmic decrease in he frequency of average co and a heavy
reesentation of very lony sizes, heavily represented in the small colonies est size frequency, was
mimicked on all other platforms where T. micranthus occurred, particularly GI-93C and GI-
116A (Fig. 6). This is similar to the observations made in Brazil by Lages et al. (2011) and
Sampaio et al. (2012), The [what were dimensions of the largest colonies found, and the what
proportion of the population at each site reachinged thoese sizes is shown ins. It is not known
whether maximum coloy size fos species was reached here, for we are not aware odataare not
available on maximum colony sizes for Tubastraea micranthus in its native habitat[?]. ? Were
they much smaller than maximum known body sizeies? This is important, as it reveals how many
individuals had reached im
15
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
29
30
Tubastraea coccinea
Densities of Tubastraea coccinea were much higher than those of T. micranthus, with the highest
densities in this survey reaching about 300 colonies/m2 – 20-fold higher than that of the new
invasive species (Fig. 7). The platforms had significantly different densities. Platform ST-185B
exhibited the highest concentrations of T. coccinea, which were equivalent to those on GI-116A,
but higher than on all other platforms (see Table 2c4 for pair-wise inter-platform comparisons).
Densities on GI-116A were higher than almost all other platforms. Densities on ST-206A were
approximately equivalent to most all other platforms except the above two plus MC-311A and
ST-185A.
Interestingly, if one considers Tthe geographic distribution of T. coccinea colony density in this
region of the northern Gulf of Mexico was through three-dimensional graphing, one finds that
the distribution looks quite similar to that of the recent invader T. micranthus (Fig. 8). The major
peaks occurred southwest of the mouth of the Mississippi River, and densities decreased radially
in all directions from there.
Discussion
The pattern reported here for the fact that, on the 14 platforms surveyed south of the Mississippi
River mouth, in which the highest densities of Tubastraea micranthus were found on Platform
GI-93-C, – the point of the original observation, by SAP indicates- confirmed our suspicions that
that platform had received a major influx of larvae from populations from one or more nearby
platforms. On the other hand, it may have been the is was most likely the initial point or
16
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
31
32
epicenter of colonizationut this is less likely, based on size-frequency information (see below).
by this species o. The original observation was fortuitous. The geographic pattern of
distribution of Tubastraea micranthus densities throughout the study region also supports these
former hypothessunderscores our belief that GI-93-C was the original epicenter of colonization,
with the spread being in all directions from there. The secondary peak at GI-116-A116A
suggests a similar relationship. Tubastraea micranthus is known to be able to double its colony
density in a single year (Loch et al., 2004). , however, implies that at one point or more, this
platform may have received a pulse of larvae from GI-93-C from a southerly current passing
over the latter platform.
It has been suggested that, in corals, size is a better indicator of population dynamics in corals
than age (Hughes, 1984; Goffredo and Lasker, 2006). Although size has been used often as a
target variable in colonial organisms (Grigg, 1975), colony age and size data and their impact on
calculations of current and future population growth can, however, be confounded (Grigg, 1975;
Hughes and Connell, 1987; Babcock, 1991; Chadwick-Furman, et al., 2000). Guzner et al.
(2012) have found that age structure without estimates of recruitment can be misleading due to
incomplete data. Bak and Meesters (1998) suggest that the C.V., mode, and skewness of a coral
population size-frequency distribution can provide valuable information regarding the population
dynamics of a coral population. Done (1988) and Fong and Glynn (1988) have used coral
colony size-frequency data to predict coral community recovery times after a major perturbation
such as a Crown-of-Thorns population explosion.
17
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
33
34
Data regarding the mean colony size-frequency distribution of the Tubastraea micranthus
colonies on these platforms have important implications for point of initial colonization,
definition of niche specificity, and the population dynamics of this species. Firstly, average
colony size did not peak at GI-93-C – the presumed point of original colonization; it peaked on
the MC-311-A311A and to some degree on MC-109A platform, being significantly higher than
all other survey platforms, and with average colony sizes clearly falling off in all directions from
there. A further analysis of MC-109A, however, indicated that the size-frequency distribution
was similar to those on most of the other platforms, being dominated by very small colonies. It
is possible that MC-311A could have been the initial site of colonization, since it possesses not
the most abundant largest population of T. micranthus, but the oldest colonies in this young set
of coral pons. If that were the case, and this platform were seeding the others, then the other
platforms would be expected to possess smaller sized colonies – which they do.
As another point of consideration, the currents in this region may be expected to flow from east
to west, particularly during the spawning season due to the Loop Current (Sturges and Blaha,
1976; Hamilton et al., 1999). Larvae may also have been carried by a counter-current (Wiseman
and Garvine, 1995) to the Western Boundary Current (Vidal Lorandi et al., 1999). This would
flow from the east to the north and west and could have carried larvae in that direction. Another
current from the east is that associated with the Tortugas Bank and Pulley Ridge, Florida (Jarrett
et al., 2000; Meyers et al., 2001). (See Sturges and Lugo-Fernandez, 2005 for a complete review
of currents in the GOM, including this region.) Any of these currents could have influenced
larval dispersal and settlement, and they suggest opportunities for future research in this area. In
18
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
35
36
addition, it is known that success of coral recruitment and growth may be regulated by a diverse
set of environmental factors, many of which vary in this region.
In all cases, however, we know that the skewness of the size-frequency distributions was high
and clearly biased towards the smallest colony sizes. This pattern is similar to that described by
McNaughton and Wolf (1979) of a rapidly expanding population, where most of a population is
comprised of pre-reproductive organisms followed by reproductive ones. Such a population
would not yet be considered stable. In addition, studies of reproduction and size-structure in red
corals have shown that reproductive output increases with size (Tsounis et al., 2006). Because of
this, we hypothesize that all of the populations observed, irrespective of average size of the
colony, are in a phase of high initial population growth.
TThe environment of MC-311-A311A is different from that of GI-93-C and may also provide a
more suitable environment for growth than in the other sites. GI. GI-93-C occurs on the
continental shelf in 64 m depth of water, and it periodically receives water from the Mississippi
River plume as it meanders throughback and forth in this region. The river plume is, of course,
characterized by high turbidity, a high sediment load, high nutrients, and low salinity (Sturges
and Lugo-Fernandez, 2005; Rabalais et al., 1996). On the other hand, MC-311-A311A occurs
beyond the edge of the continental shelf, at the head of the Mississippi Canyon. It is more
frequently characterized by blue water (low turbidity, low sediment load, low nutrients - except
for upwelling events -, , and a more stable stenohaline environment; see Rabalais et al., 1996;
Weisberg and He, 2003; Green et al., 2006). Thus, one might we hypothesize that T.
19
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
37
38
micranthus grows better than does T. coccinea in a blue-water environment than a coastal one
that is, subjected to typical coastal environmental variability.
Tubastraea coccinea’s highest densities were found on ST-185-B185B and GI-116-A116A.
Both of these sites have environments similar to GI-93-C, and are subjected regularly to water
from the Mississippi River plume. This species was also commonly observed on mid-shelf
waters subjected to coastal discharge influences in the northern Gulf of Mexico, where
hermatypic (reef-building) corals were not encountered (Sammarco 2012a). This is another
indication that there may be of differences in niche specificity and preferred habitat between
these two congeners. We hypothesize that T. coccinea tolerates and perhaps thrives better in
coastal or river-influenced waters that are not as well tolerated by T. micranthus or by most other
tropical reef corals.
This observation raises an interesting point regarding potential impacts of Tubastraea
micranthus vs. T. coccinea. T. coccinea invaded the western Atlantic in the 1940s (Cairns, 2000;
Humann and DeLoach, 2002; Fenner and Banks, 2004). Since that time, it has spread as far
south as Brazil (Figueira de Paula and Creed, 2004) and as far north as the Flower Garden Banks
(Fenner, 1999, 2001; Fenner and Banks, 2004), the Florida Keys (Shearer, 2008), and platforms
in the northern Gulf of Mexico (Sammarco et al., 2012a). Tubastraea spp. in Brazil are showing
signs of expansion and disruption of native species (Lages et al., 2011; Sampaio et al., 2012).
During this period, it has become evident that populations of this species haveare able to nearly
20
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
39
40
monopolized artificial hard-bottom substrata such as offshore platforms. In no case of which we
are aware, however, has ve there been reports of this species dominateding natural, exposed coral
reef environments, despite the fact that it does has been reported to occur on these natural reefs
in the western Atlantic in both shallow and deep environments (Sammarco, 2012b; Hickerson et
al., 2006).
We hypothesizepropose that the reason for low colony densities this deficit of colonies on natural
reefs is that T. coccinea may cannot compete well for space with the natural sessile epibenthic
fauna and flora found at least on a coral reefs it has colonized in the western Atlantic thus far. It
is also possible that coral reef, and/or there are naturally occurring predators there that
suppressng their populations when they are occur fully exposed, as has been suggestLages et al.
(2010). . On these natural reefs, the colonies observed tend to be found in their natural numbers
and ohabitat occupn the Indo-Pacific region, which areis cryptic and in low numbers, associate
with other ahermatypic corals (cite rerences[?]). The concern here is that the natural
environment for T. micranthus in the Indo-Pacific is on the upper surfaces of reef substratum,
fully exposed (Schuhmacher, 1984; Fuzaki, 2011). If and when this species encounters a natural
Atlantic coral reef, it is possible that it is possible that may be successful at outcompeting
naturally occurring sessile epibenthic fauna and flora for space. Its degree of toxicity and degree
of palatability to predators, which could potentially control its populations, are currently
unknown.
21
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
41
42
The size-frequency distributions of Tubastraea micranthus are suggest that theseindicative of a
populations may be in an a high explosive growth phase (McNaughton and Wolf, 1979). In the
case of Platform MC-109-A109A, almost 60% of the colonies are between 1 and 100 cm2 in area
or about 5 cm in diameter, while the largest size colony was 1,200 cm2, or ~40 cm in diameter.
We are unaware of what the maximum size for this species is in its natural environment, but
available images indicate that it is on the order of one meter. (ref[?]; determine whet. In
addition, the size-frequency distributions were highly consistent from platform to platform; thus,
highthis explosive aspectt of population growth is occurring on across all of the newly colonized
platforms. It is possible that Alternately, the similarpatterns of all these populations may indicate
that they all have reached a mature, stable size structurestructure, but such is unlikely, given the
assumed ti of the introduction. s impossible to tell the difference unlample populations at
various points in time] The shape of this single-point size-frequency distribution is similar to that
of a “wide-based pyramid”, described by human demographers to be indicative of human
populations with a high growth rate and low doubling times and Oertel, 196
, e.g., T. coccinea, where there is more data. Are there data on temporal changes in T. coccinea
through time after invasion? ]. TwoOne factors limiting our interpretations of population
growth are firstly, of density and size-frequency data is that they represent only one sampling
point in time. Having a temporal data sequence would maddress som whether these populationss
are stable or dynamic. From other studies of expanding populations, howeverns ([gen refnd
coral refs?]), we assume at this point in time that they are dynamic. Sncy data is in itself
limiting. Nonetheless, we offer these explanatory hypotheses for consideration. Having a
temporal sequence would more easily address some these hypotheses.
22
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
43
44
India, China, and Indonesia (Miller, 2000).
A problem with your analysis is that you have measured the new invaders at only one point in
time, and so have only static data on both population density and body size patterns.]
We believe that we have confirmed–e data presented here suggestindicate that Tubastraea
micranthus has appears to hhas successfully invaded the northern GOMulf of Mexico and mayis
exhibiting signs of producing rapidly expanding its populations in thise region. Its congener, T.
coccinea, has already demonstrated a strong formidable capability for geographic range
extensionies in this area. Preliminary data on depth distribution and competitive abilities
(Sammarco et al., work in progress) give cause for further concern about the invasion of T.
micranthus. [We believet awa a suggest that T. micranthus has the ability for extensive
geographic expansion in the western Atlantic Ocean if left unchecked. Complete eradication of
introduced marine species is possible, but such can be difficult, and eradication efforts must be
swift and complete if they are to be effective (Fitzhugh and Rouse, 1999). In thatis case, it is
possible that[we believe that the window for action may ae is closing rapidly. If introduced
populations are left unchecked for too long, the new speciesy newly introduced populations will
become well integrated into its target the invaded?original community, creating a new
community structure and stable equilibrium, with defining a new f set of ecological interactions
[betweenamong species (Mooney and Cleland, 2001; Krushelnycky and Gillespie, 2008). In that
case, eradication may actually create more problems than it solves (Bergstrom et al., 2009;
Casey, 2009). At this point, we stand at a branch in the decision-making road regarding
eradication of Tubastraea micranthus. Thriefly tell the reader: at what stage do any decisions
23
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
45
46
currently exist regarding eradication, within the management agencies responsible for Gulf
ecological health, such as your funding agencies listed below? In your experience, or in the lite
Invasive-Sp-52-Ms-1.doc
24
521
522
523
524
525
526
527
528
47
48
Acknowledgements
We express our deep-felt thanksa to the following for their topside assistance in the field:
LUMCON - C. Sevin, T. Widgeon, M. Wike; M/V Fling – B. Allen, K. Bush, K. Dies, M.
McReynold, B. Oldham, M. Spurgeon, J. Tyler; NASA/US Air Force – D. Perrenod; Others – M.
Gaskill. For their financial support of the project, we extend our thanks to the Bureau of Ocean
Energy Management (BOEM), US Department of Interior through the Louisiana State University
Coastal Marine Institute (CMI) program, under the direction of L. Rouse and S. Welsh, under
grant #M08AC12865___________________.
25
529
530
531
532
533
534
535
536
537
538
539
49
50
References
Albins, MA, Hixon, MA (2011) Worst case scenario: potential long-term effects of invasive
predatory lionfish (Pterois volitans) on Atlantic and Caribbean coral-reef communities.
Envtl Biol Fish DOI 10.1007/s10641-011-9795-1
Anonymous (1997) Zebra mussels invade southern waters. Force Five 14 (vp.)
Ayre, DJ, Resing, JM (1986) Sexual and asexual production of planulae in reef corals. Mar Biol 90:187-
190.
Babcock, R.C. (1991) Comparative demography of three species of scleractinian corals using age- and
size-dependent classifications. Ecol Monogr 61:225-244.
Bak, RPM, Meesters, EH (1998) Coral population structure: The hidden information of colony size-
frequency distributions. Mar Ecol Prog Ser 162:301-306
Baker, P, Fajans, J, Baker, SM, Berquist, D (2006) Green mussels in Florida, USA: Review of trends
and research. World Aquacult 37:43
Bax, N., Williamson, A., Gonzalez, E., Geeves, W. (2003) Marine alien invasive species: A threat to
global diversity. Mar Policy 27:313-323
http://www.sciencedirect.com/science/article/pii/S0308597X03000411 (last viewed on Sept. 17,
2013)
Bergstrom, DM, Lucieer, A, Kiefer, K, Wasley, J, Belbin, L, Pedersen, TK, Shown, SL (2009) Indirect
effects of invasive species removal devastate World Heritage Island. J Appl Ecol 46:73-81
Buhs, JB (2004) The fire ant wars, Univ. Chicago Press, Chicago, IL, 216 pp.
Cairns, SD (2000) Revision of the shallow-water azooxanthellate Scleractinia of the western Atlantic.
Stud. Nat. Hist. Caribb. Reg. 75:1-240
26
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
51
52
Cairns, SD (2001) A generic revision and phylogenetic analysis of the Dendrophylliidae (Cnidaria:
Scleractinia). Smithson. Contrib. Zool. 2001 615:75.
Cairns, SD, Zibrowius, H (1997) Cnidaria Anthozoa: Azooxanthellate Scleractinia from the Philippine
and Indonesian regions. Mémoires du Muséum national d'histoire naturelle 172:27-243
Casey, M (2009) Species eradication backfires big time. CBS News, Jan. 13, 2009,
http://www.cbsnews.com/stories/2009/01/13/tech/main4719190.shtml
Chadwick-Furman, N.E., Goffredo, S., Loya, Y. (2000) Growth and population dynamic model of the
reef coral Fungia granulosa Klunzinger 1879 at Eilat, northern Red Sea. J Exp Mar Biol Ecol
249:199-218
Chapman, AS (1999) From introduced species to invader: What determines variation in the success of
Codium fragile ssp. tomentosoides (Chlorophyta) in the North Atlantic Ocean? Helgol
Meeresunters 52:77-289
Chapman, D, Ranelletti, M, Kaushik, S (2006) Invasive marine algae: An ecological perspective. Bot
Rev 72:153-178.
Chesapeake Bay Commission (1995) The introduction of non-indigenous species to the Chesapeake Bay
via ballast water. Strategies to decrease the risks of future introductions through ballast water
management. Chesapeake Bay Comm., Annapolis, MD, USA.
Christmas, J, Eades, R, Cincotta, D, (and others). 2001. History, management, and status of introduced
fishes in the Chesapeake Bay basin. Proceedings of conservation of biological diversity: A key to
the restoration of the Chesapeake Bay ecosystem and beyond, pp. 97-116.
Craig, G.Y., Oertel, G. (1996) Deterministic models of living and fossil populations of animals. Quart J
Geol Soc 122:315-354. doi: 10.1144/gsjgs.122.1.0315
Dextrase, AJ, Mandrak, NE (2006) Impacts of alien invasive species on freshwater fauna at risk in
Canada. Biol Invas 8:13-24.
27
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
53
54
Done, TJ (1988) Simulation of recovery of pre-disturbance size structure in populations of Porites spp.
damaged by the crown of thorns starfish Acanthaster planci. Mar Biol 100:51-61
Elton, CS (2000) The ecology of invasions by animals and plants. Univ. Chicago Press, Chicago, 196
pp.
Fenner, D (1999) New observations on the stony coral (Scleractinia, Milleporidae, and Stylasteridae)
species of Belize (Central America) and Cozumel (Mexico). Bull Mar Sci 64:143-154
Fenner, D (2001) Biogeography of three Caribbean corals (Scleractinia) and the invasion of Tubastraea
coccinea into the Gulf of Mexico . Bull Mar Sci 69:1175-1189
Fenner, D, Banks, K (2004) Orange cup coral Tubastraea coccinea invades Florida and the Flower
Garden Banks, northwestern Gulf of Mexico. Coral Reefs 23:505-507
Figueira de Paula, A., Creed, JC (2004) Two species of the coral Tubastraea (Cnidaria, Scleractinia) in
Brazil: A case of accidental introduction. Bull Mar Sci 74:175-183.
Fitzhugh, K, Rouse, GW (1999) A remarkable new genus and species of fan worm (Polychaeta:
Sabellidae: Sabellinae) associated with marine gastropods. Invert Biol 118:357-390.
DOI: 10.2307/3227007
Fong, P, Glynn, PW (1988) A dynamic size-structured population model: Does disturbance
control size structure of a populations of the massive coral Gardineroseris planulata in
the eastern Pacific? Mar Biol 130:663-674
Issue 4Gardineroseris planulata in the Eastern Pacific?
P. Fong ,
28
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
55
56
Glynn, PW, Colley, SB, Mate, JL, Cortes, J, Guzman, HM, Bailey, RL, Feingold, JS, Enochs, IC (2008a)
Reproductive ecology of the azooxanthellate coral Tubastraea coccinea in the equatorial eastern
Pacific: Part V. Dendrophylliidae. Mar Biol 153:529-544
Glynn, PW, Colley, SB, Mate, JL, Cortes, J, Guzman, HM, Bailey, RL, Feingold, JS, Enochs, IC
(2008b) Reproductive ecology of the azooxanthellate coral Tubastraea coccinea in the
equatorial eastern Pacific: Part V. Dendrophylliidae (erratum). Mar Biol 154:199.
Goffredo, S., Lasker, H.R. (2006) Modular growth of a gorgonian coral can generate
predictable patterns of colony growth. J Exp Mar Biol Ecol 336:221-229
Golden Software (2002) Surfer 8: User’s Guide. Golden Software, Inc, Golden, Colorado, USA
Graham, W.M., D.L. Martin, D.L. Felder, V.L. Asper, and H.M. Perry. 2003. Ecological and economic
implications of a tropical jellyfish invader in the Gulf of Mexico. Biol. Invasions 5: 53-69.
Graham, WM, Bayha, KM (2008) Assessing oil and gas platforms for settlement of jellyfish polyps in
the northern Gulf of Mexico . Proc. 24th Gulf of Mexico Information Transfer Meeting, US Dept.
Interior, Minerals Management Service, New Orleans, LA, USA, OCS Report No. 2008-012, p.
348.
Green, RE, Bianchi, TS, Dagg, MJ, Walker, ND, Breed, GA (2006) An organic carbon budget
for the Mississippi River turbidity plume and plume contributions to air-sea CO2 fluxes
and bottom water hypoxia. Estuar Coasts 29:579–597.
Griffiths, RW (1991) Spatial distribution and dispersal mechanisms of zebra mussels in the Great Lakes
basin. J Shellfish Res 10:1- 248
Grigg, RW (1975) Age structure of a longevous coral: A relative index of habitat suitability and
stability. Am Nat 109:647-657
Guzner, B., Novoplansky, A., Chadwick, N.E. (2012) Population dynamics of the reef-building coral
Acropora hembrichii as an indicator of reef condition. Mar Ecol Prog Ser 333:143-150
29
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
57
58
Halford, A, Cheal, AJ, Ryan, D, Williams, D McB (2004) Resilience to large-scale disturbance
in coral and fish assemblages on the Great Barrier Reef. Ecol. 85:1892-1905.
http://dx.doi.org/10.1890/03-4017
Hamilton, P., Fargion, G.S., Biggs, D.C. (1999) Loop current eddy paths in the western Gulf of
Mexico. J. Phys Oceanogr 29:1180-1207
Hamner, RM, Freshwater, D, Whitfield, P (2007) Mitochondrial cytochrome b analysis reveals two
invasive lionfish species with strong founder effects in the western Atlantic . J Fish Biol 71:214-
222
Hebbinghaus, R (2001) Larval development, hatching and care of the stony coral (Tubastraea
cf. coccinea) in a closed system. Bull. de l’Institut Oceanographique, Monaco, No.
Special 20, fascicule 1, 5 pp.
Hickerson, EL, Schmahl, GP, Weaver, DC (2006) Patterns of deep coral communities on reefs and
banks in the northwestern Gulf of Mexico . EOS Trans Am Geophys Union 87 (36) (suppl.)
Hicks, DW, and Tunnell, JW Jr (1993) Invasion of the south Texas coast by the edible brown mussel
Perna perna (Linnaeus, 1758). Veliger 63:92-94 .
Hindar, K, Fleming, IA, McGinnity, P, Diserud, O (2006) Genetic and ecological effects of salmon
farming on wild salmon: Modeling from experimental results. ICES J Mar Sci 63:1234-1247
30
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
59
60
Hughes, TP (1984) Population dynamics based on individual size rather than age: A general model with
a reef coral example. Am Nat 123:778-795
Hughes, TP, Connell, JH (1987) Population dynamics based on size or age? A reef-coral analysis. Am
Nat 129:818-829
Humann, P, DeLoach, N (2002) Reef coral identification: Florida, Caribbean, Bahamas, including
marine plants. New World Publs, Jacksonville, Florida, USA, 278+ pp
ICES (2002). Report of the ICES/IOC/IMO study group on ballast and other ship vectors - Gothenburg,
Sweden, 18-19 March 2002. ICES Council Meeting Documents, ICES, Copenhagen, Denmark
Jarrett, B.D., Hine, A.C., Neumann, A.C., Narr, D., Locker, S., Malinson, D., Jaap, W. (2000) Deep
biostromes at Pulley Ridge: Southwest Florida carbonate platform. In Hallock, P., French, L.
(Eds.), Diving for science in the 12st century. Am. Acad. Underwater Sci, Nahant, MA, USA, p.
14
Johnson, LE, Carlton. JT (1996) Post-establishment spread in large-scale invasions: Dispersal
mechanisms of the zebra mussel Dreissena polymorpha . Ecol 77:1686-1690
Johnson, WR, Niller, PP (1994) SCULP drifter study in the northwest Gulf of Mexico. Am Geophys
Union, Fall Meeting, San Francisco, 052C-8
Kerr, SJ, Brousseau, CcS, Muschett, M (2005) Invasive aquatic species in Ontario: A review and
analysis of potential pathways for introduction. Fisheries 30:21-30.
Kormondy, E.J. (1969) Concepts of ecology. Prentice-Hall, Englewood Cliffs, New Jersey, USA
Krushelnycky, P.D. and R.G. Gillespie. 2008. Compositional and functional stability of
arthropod communities in the face of ant invasions. Ecol. Applic. 18: 1547-1562.
http://dx.doi.org/10.1890/07-1293.1
Lages, B.G., Fleury, B.G., Menegola, C., Creed, J.C. (2011) Change in tropical rocky shore
communities due to an alien coral invasion. Mar Ecol Prog Ser 438:85-96
31
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
61
62
Lages, B.G., Fleury, B.G., Pinto, A.C., Creed, J.C. (2010) Chemical defenses against generalist
fish predators and fouling organisms in two invasive ahermatypic corals in the genus
Tubastraea. Mar Ecol 31:473-482. DOI: 10.1111/j.1439-0485.2010.00376.x
Liffman, M (1997) Aquatic nuisance species with a focus on zebra mussels - Southern Region . Proc 7th
Int Zebra Mussel and Aquatic Nuisance Species Conf 1997, New Orleans, LA, Jan. 1997, p 91-95
Loch, K., Loch, W., Schuhmacher, H., See, W.R. (2004) Coral recruitment and regeneration on a
Maldivian reef four years after the coral bleaching event of 1998. Part 2: 2001-2002. Mar Ecol
25:145-154 DOI: 10.1111/j.1439-0485.2004.00021.x (last viewed on September 17,
2013)
McNaughton, S.J. and L.L. Wolf. 1979. General Ecology. Holt, Rinehart, and Winston, New
York.
Meyers, S.D., Siegel, E.M., Weisberg, R.H. (2001) Observations of currents on the Wesst
Florida shelf break. Geophys Res Lett 28:2037-2040
Miller, G.T. 2000. Living in the Environment: Principles, connections, and solutions.
Brooks/Cole Publ., Pacific Grove, California, USA.
Minchin, D, Gollasch, S (2003) Fouling and ships' hulls : How changing circumstances and spawning
events may result in the spread of exotic species. Biofouling 19:111-122
Mooney, HA, Cleland, EE (2001) The evolutionary impact of invasive species. Proc Nat Acad.
Sci 98:5446-5451
Muzaki, F. (2011) Tubastraea micranthus – Karimunjawa 1 (image).
http://www.fobi.web.id/fbi/updates?g2_albumId=17383&g2_itemId=53498 (last viewed
Sept. 23, 2013).
32
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
63
64
Osman, R, Shirley, T (eds) (2007) The Gulf of Mexico and Caribbean marine invasive species
workshop: Proc and final rept., Harte Res Inst, Texas A&M Univ, Corpus Christi, TX, 47 p
Pagad, S (2007) Tubastraea coccinea (corail). Global Invasive Species Database, Invasive Species
Specialist Group, IUCN Species Survival Commission.
http://www.issg.org/database/species/ecology.asp?si=1096&fr=1&sts=&lang=FR
Pederson, J (2000) Marine bioinvasions: Proceedings of the first national conference. Proc.1st Nat.
Conf. on Marine Bioinvasions, Cambridge, MA, USA, January 24-27, 2000, 427 pp
Pederson, 2000
Perry, HM, Graham, M (2000) The spotted jellyfish: Alien invader. Report to NOAA Mississippi-
Alabama Sea Grant, Hattiesburg, Mississippi, USA, 2000.
Rabalais, NN, Turner, RE, Dortch, Q, Wiseman, WJ Jr, Sen Gupta, BK (1996) Nutrient
changes in the Mississippi River and system responses on the adjacent continental shelf.
Estuar 19:386-407
Ram, JL, Palazzolo, SM (2008) Globalization of an aquatic pest: Economic costs, ecological
outcomes, and positive applications of zebra mussel invasions and expansions .
Geography Compass 2:1755-1776
Rohlf, FJ, Slice, DE (1996) BIOMstat for Windows: Statistical software for biologists, Vs. 3.2
Exeter Software, Setauket, NY, USA
Sammarco, PW, Atchison, A, Boland, GS (2004) Expansion of coral communities within the
northern Gulf of Mexico via offshore oil and gas platforms. Mar Ecol Prog Ser 280:129-
143
Sammarco, PW, Atchison, AD, Brazeau, DA, Boland, GS, Lirette, A (2007a) Expansion of scleractinian
corals across the N. Gulf of Mexico: A bird’s eye view of large-scale patterns and genetic
affinities. Proc Austral Mar Sci Assn (AMSA), Melbourne, Vic, Australia, Abstract
33
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
65
66
Sammarco, PW, Brazeau, DA, Atchison, AD, Boland, GS, Lirette, A (2007b) Coral distribution,
abundance, and genetic affinities on oil/gas platforms in the N. Gulf of Mexico: A preliminary
look at the Big Picture. Proc US Dept. Interior Minerals Management Service Information
Transfer Meeting, New Orleans, Jan 2007
Sammarco, PW, Brazeau, DA, Atchison, AD, Boland, Hartley, S, Lirette, A (2008) Distribution,
abundance, and genetics of corals throughout the N. Gulf of Mexico: The world’s largest coral
settlement experiment. Proc 11th Int Coral Reef Symp, Fort Lauderdale, July 2008, Abstract
Sammarco, PW, Porter, SA, Cairns, SD (2010) New invasive coral species for the Atlantic
Ocean - Tubastraea micranthus (Cairns and Zibrowius 1997) (Colenterata, Anthozoa,
Scleractinia): A potential major threat? Aquat Invasions 5:131-140.
Sammarco, PW, Atchison, AD, Boland, GS, Sinclair, J, Lirette, A (2012a) Geographic
expansion of hermatypic and ahermatypic corals in the Gulf of Mexico, and implications
for dispersal and recruitment. J Exp Mar Biol Ecol 436-437:36-49.
http://dx.doi.org/10.1016/j.jembe.2012.08.009
Sammarco, PW, Brazeau, DA, Sinclair J (2012b) Genetic connectivity in scleractinian corals
across the northern Gulf of Mexico: Oil/gas platforms, and relationship to the Flower
Garden Banks. PLOS-One 7(4): e30144. doi:10.1371/journal.pone.0030144
Sammarco, P.W., Lirette, A., Tung, Y.F., Genazzio, M., Sinclair, J. (in press; 2013) Coral
community development on “Rigs-to-Reefs” vs. standing oil/gas platforms: Artificial
reefs in the Gulf of Mexico. ICES J. Mar. Sci.
Sampaio, C.I.S., Miranda, R.J., Maia-Nogueira, R.M., Nunes, J.A.C.C. (2012) New occurrences
of the non-indigenous orange cup corals Tubastraea coccinea and T. tagusensis
34
735
736
737
738
739
740
741
742
743
744
745
746
747
748
752
753
754
755
756
757
758
759
760
67
68
(Scleractinia: Dendrophylliidae) in southwestern Atlantic. Check List 8:528-530.
http://www.checklist.org.br/getpdf?NGD202-11
Sapota, MR (2004) The round goby ( Neogobius melanostomus ) in the Gulf of Gdansk - a
species introduction into the Baltic Sea. Hydrobiol 514:219-224
Schmahl, GP (2003) Biodiversity associated with topographic features in the northwestern Gulf of
Mexico. Proc US Dept. Interior, Minerals Management Service Information Transfer Meeting,
Gulf of Mexico, OCS Region, Kenner, Louisiana
Schmahl, GP, Hickerson. EL (2006) Ecosystem approaches to the identification and characterization of
a network of reefs and banks in the northwestern Gulf of Mexico . EOS Trans. Am. Geophys.
Union 87, (36), suppl
Schumacher, H (1984) Reef-building properties of Tubastraea micranthus (Scleractinia,
Dendrophylliidae), a coral without zooxanthellae. Mar Ecol Prog Ser 20:93-99
Shearer, TL (2008) Range expansion of an introduced coral: Investigating the source and ecological
impact of the invasion. 2008 Ocean Sciences Meeting: From the Watershed to the Global
Ocean, Orlando, FL (USA), 2-7 Mar 2008
Sokal, RR, Rohlf, FJ (1981) Biometry. WH Freeman Publ, San Francisco, California, USA
Sturges, W., Blaha, J.P. (1976) A western boundary current in the Gulf of Mexico. Science
92:367-369
Sturges, W., Lugo-Fernandez, A. (2005) Circulation in the Gulf of Mexico: Observations and
models. Monogr. No. 161, Am. Geophys. Union, Washington, DC, USA, 360 pp +
Tsounis, G, Rossi, S, Aranguren, M, Gili, J-M, Arntz, W (2006) Effects of variability and
colony size on the reproductive output and gonadal development cycle of the
Mediterranean red coral (Corallium rubrum L.). Mar Biol 148:513-527
35
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
69
70
Trowbridge, CD (1998) Ecology of the green macroalga Codium fragile (Suringar) Hariot 1889:
invasive and non-invasive subspecies. Oceanogr Mar Biol Annu Rev 36:1-64
Vidal Lorandi, F.V., Vidal Lorandi, V.M.V., Rodriguez Espinoza, P.F., Sambrano Salgado, L., Portilla
Casilla, J., Rendon Villalobos, J.R., de la Cruz, B.J. (1999) Gulf of Mexico circulation. Rev Soc
Mex Hist Nat 49:1-15.
Weidema, IR (Ed) (2000) Introduced species in the Nordic countries. Nord 13, 242 pp.
Weisberg, RH, He, R (2003) Local and deep-ocean forcing contributions to anomalous water
properties on the west Florida shelf. J. Geophys. Res: Oceans (1978-2012), 208,
Abstract
Whitfield, PE, Gardner, T, Vives, SP, Gilligann, MR, Courtenay, WR Jr, Ray, GC, Hare, JA (2002)
Biological invasion of the Indo-Pacific lionfish Pterois volitans along the Atlantic coast of North
America. Mar Ecol Prog Ser 235:289-297
Williams, DMcB (1982) Patterns in the distribution of fish communities in the central Great
Barrier Reef. Coral Reefs 1:35-43
Williams, SL (2007) Introduced species in seagrass ecosystems: Status and concerns. J Exp
Mar Biol Ecol 350:89-110
Williams, S.L., Smith, J.E. (2007) A global review of the distribution, taxonomy, and impacts
of introduced seaweeds. Annu Rev Ecol Evol Syst 38:327–59
Wiseman, W.J., Garvine, R.W. (1995) Plumes and coastal currents near large river mouths.
Estuaries 18:509-517.
Womersley, H.B.S. (Ed.) (2003) The marine benthic flora of southern Australia. Part IIID:
Ceramiales – Delesseriaceae, Sarcomeniaceae, Rhodomelaceae. Australian Biological
36
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
71
72
Resources Study, Canberra, ACT, Australia, Flora of Australia Supplementary Series No.
18, 553 pp.
Wonham, MJ, Carlton, JT, Ruiz, GM, Smith, LD (2000) Fish and ships: Relating dispersal
frequency to success in biological invasions. Mar Biol 136:1111-1121
Zenetos, A., Cinar, M.E., Pancucci-Papadopoulou, M.A., Harmelin, J.G., Furnari, G., Andaloro,
F., Belou, N., Streftaris, N., Zibrowius, H. (2005) Annotated list of marine alien species
in the Mediterranean with records of the worst invasive species. Mediterr Mar Sci 6:63-
118. DOI: 10.12681/mms.186
37
809
810
811
812
813
814
815
816
817
818
819
820
73
74
Figure Legends
Figure 1. Map of the north-central Gulf of Mexico showing locations of the 14 offshore oil
and gas platforms studied. Platform GI-93-C (triangle) represents the site of first
sighting of Tubastraea micranthus (Sammarco et al., 2010).
Figure 2. Density of Tubastraea micranthus on 14 offshore oil/gas platforms in the northern
Gulf of Mexico. Densities shown in no./m2 with 95% confidence limits.
Densities are highly significantly different from each other (p < 0.001, one-way
ANOVA). Data transformed via square-root of (Y + 0.5) for purposes of
normalization (see Sokal and Rohlf, 1985). See Table 2a for details of inter-
platform comparisons. See Table 1 for sample sizes.
Figure 3. Geographic distribution of the density of Tubastraea micranthus in the northern
Gulf of Mexico, south of the Mississippi River mouth. Note the primary peak (at
GI-93C, the presumed location of initial invasion), the secondary peak (at GI-
116A) indicating a strong southerly spread, and the dissipation of density radially
from these points. Numnbers represent study platforms. See Table 1 for platform
names.
Figure 4. Mean colony size of Tubastraea micranthus in the northern Gulf of Mexico, south
of the Mississippi River mouth. Note that the largest average colony sizes are
found on MC-311A, a potential original site of colonization and one a site which
38
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
75
76
occurs in blue water within the Mississippi Canyon, unlike many of the other
sites. Significant difference between colony sizes on different platforms (p <
0.001, one-way ANOVA; see Table 2b for detailed comparisons). Data
transformed by square root (Y + 0.5) for normalization purposes. See Table 1 for
sample sizes.
Figure 5. Geographic distribution of the mean colony size of Tubastraea micranthus in the
northern Gulf of Mexico, south of the Mississippi River mouth. Note the primary
peak (at MC-311A, within the Mississippi Canyon) and how average colony size
decreases radially from that point, indicating that this site might possess the best
environmental conditions for growth for this species. Numbers represent study
platforms. See Table 1 for platform names.
Figure 6. Size-frequency distribution of colonies of Tubastraea micranthus on three
platforms in the northern Gulf of Mexico, near the Mississippi River mouth –MC-
109A (top), GI-93C (bottom left), and GI-116A (bottom right). Examplary of
distributions found on all platforms. Note the abundant over-representation of
smaller-sized colonies, potentially indicating high explosive population growth
with low doubling times. Platform MC-109A: Mean = 198.6 cm2, s.d. = 281.14,
ni = 47, g1 = 1.92, g2 = 3.36. Platform GI-116A: Mean = 34.7 cm2, s.d. = 45.60,
ni = 24, g1 = 2.74, g2 = 8.23. Platform GI-93C: Mean = 33.5 cm2, s.d. = 94.18, ni
= 472, g1 = 7.19, g2 = 63.11.
39
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
77
78
Figure 7. Density of Tubastraea coccinea in the northern Gulf of Mexico on 14 platforms
off the mouth of the Mississippi River. Densities shown in no./m2 with 95%
confidence limits. Densities are highly significantly different from each other (p
< 0.001, one-way ANOVA). Data transformed via square-root of (Y + 0.5) for
purposes of normalization (see Sokal and Rohlf, 1985). See Table 2c4 for details
of inter-platform comparisons. See Table 1 for sample sizes.
Figure 8. Geographic distribution of the density of Tubastraea coccinea in the northern
Gulf of Mexico, south of the Mississippi River mouth. Note the primary peak (at
ST-185B and GI-116A), exhibiting a distribution pattern similar to that of T.
micranthus. Also note the dissipation of density radially from these points.
Numbers represent study platforms. Platform names given in Table 1.
40
867
868
869
870
871
872
873
874
875
876
877
878
79
80
Table Legends
Table 1. List of 14 platforms in the northern Gulf of Mexico, near the mouth of the
Mississippi River, video-surveyed by ROV for the ahermatypic invasive Indo-
Pacific corals Tubastraea micranthus and T. coccinea. Platform number, name,
owner, and latitude and longitude of geographic location, and number of quadrats
analyzed per platform provided.
Table 2. (a) Summary of results of a posteriori multiple comparisons of means tests
performed on mean colony densities of Tubastraea micranthus on 14 oil/gas
platforms in the northern Gulf of Mexico. T’, T-K, and GT-2 tests were used.
Results of pairwise comparisons shown. Platforms are shown in order of density,
high to low. An asterisk denotes a significant difference between coral densities
on two given platforms. (b)
Table 3. Summary of results of a posteriori multiple comparisons of means tests
performed on average colony sizes of Tubastraea micranthus on 14 oil/gas
platforms in the northern Gulf of Mexico. T’, T-K, and GT-2 tests were used.
Results of pairwise comparisons shown. Platforms are shown in order of average
colony size, high to low. An asterisk denotes a significant difference between
coral colony sizes on two given platforms.(c) Summary of results
41
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
81
82
Table 4. Summary of results of a posteriori multiple comparisons of means tests
performed on mean colony densities of Tubastraea coccinea on 14 oil/gas
platforms in the northern Gulf of Mexico. T’, T-K, and GT-2 tests were used.
Results of pairwise comparisons shown. Platforms are shown in order of density,
high to low. An asterisk denotes a significant difference between coral densities
on two given platforms.
42
901
902
903
904
905
906
907
908
83
84
Figure 1.
43
909
910
911
912
913
914
85
86
Figure 2.
44
0
5
10
15
20
25
MC-109A
ST-206A
GI-93-C
ST-185-B
GI-94-B
ST-185-A
GI-116-A
GI-115-A
MC-311-A
GI-90-A
SP-87D
SP-89B
ST-81A
ST-75JA(B)
Tubastrea micranthus
Mean Density by Platform
Mean Density (per m
2
)
Platform
915
916
917
918
919
920
87
88
45
921
89
90
Figure 3.
46
922
923
924
91
92
47
925
926
927
93
94
Figure 4.
48
Tubastrea micranthus
Mean Colony Size by Platform
Mean Colony Size (cm
2
)
y
MC-109A
ST-206A
GI-93-C
ST-185-B
GI-94-B
ST-185-A
GI-116-A
GI-115-A
MC-311-A
GI-90-A
SP-87D
SP-89B
ST-81A
ST-75JA(B)
Platform
_
10
_
100
_
500
_
1000
_
1500
_
2500
928
929
930
931
932
933
934
95
96
49
935
97
98
Figure 5.
50
936
937
938
99
100
51
939
940
941
942
101
102
Figure 6.
52
943
944
945
946
947
103
104
Figure 7.
53
0
100
200
300
400
500
600
Tubastrea coccinea
Mean Density by Platform
Mean Density (per m
2
)
Platform
MC-109A
ST-206A
GI-93-C
ST-185-B
GI-94-B
ST-185-A
GI-116-A
GI-115-A
MC-311-A
GI-90-A
SP-87D
SP-89B
ST-81A
ST-75JA(B)
948
949
950
951
952
953
954
955
105
106
54
956
107
108
Figure 8.
55
957
958
959
109
110
56
960
961
962
963
964
111
112
Table 1.
Platform
Code Owner Latitude Longitude
GI-90A-1 Apache Corp. 28.575144 -90.072429
GI-90A-2 Apache Corp. 28.575144 -90.072429
GI-93C Apache Corp. 28.548886 -90.068677
GI-115A Walter Oil & Gas Corporation 28.3076123 -90.0219665
GI-116A Apache Corp. 28.30928306 -90.07054334
MC-109A Stone Energy Corporation 28.86467752 -88.93079054
MC-311A Apache Corp. 28.642636 -89.794241
SP-87D Apache Corp. 28.72001853 -89.43078669
SP-89B Apache Corp. 28.680464 -89.387596
ST-75-
JA(B) Stone Energy Corporation 28.76955709 -90.74085664
ST-81A Stone Energy Corporation 28.78656092 -90.42747823
ST-185A
Black Elk Energy Offshore Operations,
LLC 28.495501 -90.203098
ST-185B
Black Elk Energy Offshore Operations,
LLC 28.47493 -90.235942
ST-206A Apache Corp. 28.45372522 -90.38341283
Platform Number of
Numbe
r Code Owner Latitude Longitude Quadrats
1 GI-90A-1 Apache Corp. 28.575144 -90.072429 23
2 GI-90A-2 Apache Corp. 28.575144 -90.072429 129
3 GI-93C Apache Corp. 28.548886 -90.068677 125
4 GI-115A Walter Oil & Gas Corporation 28.3076123 -90.0219665 44
5 GI-116A Apache Corp. 28.30928306
-
90.07054334 44
6 MC-109A Stone Energy Corporation 28.86467752
-
88.93079054 88
7 MC-311A Apache Corp. 28.642636 -89.794241 174
8 SP-87D Apache Corp. 28.72001853
-
89.43078669 79
9 SP-89B Apache Corp. 28.680464 -89.387596 90
57
965
966
967
113
114
10
ST-75-
JA(B) Stone Energy Corporation 28.76955709
-
90.74085664 12
11 ST-81A Stone Energy Corporation 28.78656092
-
90.42747823 18
12 ST-185A
Black Elk Energy Offshore Operations,
LLC 28.495501 -90.203098 87
13 ST-185B
Black Elk Energy Offshore Operations,
LLC 28.47493 -90.235942 22
14 ST-206A Apache Corp. 28.45372522
-
90.38341283 50
58
968
969
970
971
115
116
Table 2a.
Platform
Name
GI-
93C
GI-
116A
MC-
109A
ST-
206A
SP-
87D
MC-
311A
G-
115A
SP-
89B
GI-
90A
ST-
185A
ST-
185B
GI-
94B
ST-
81A
ST-
75JA(B)
GI-93C * * * * * * * * * * *
GI-116A * * * *
MC-
109A
ST-206A
SP-87D
MC-
311A
G-115A
SP-89B
GI-90A
ST-185A
ST-185B
GI-94B
ST-81A
ST-
75JA(B)
59
972
973
974
117
118
Table 2b3.
Platform
Name
MC-
311A
MC-
109A
ST-
206A
SP89-
B89B SP-87D GI-
116A GI-93C GI-90A GI-115A
MC-311A * * * * * * * *
MC-109A * * *
ST-206A *
SP89-
B89B
SP-87D *
GI-116A
GI-93C
GI-90A
GI-115A
60
975
976
977
978
979
119
120
Table 2c4.
ST-
185B
GI-
116A
MC-
311A
ST-
185A
GI-
94B
ST-
206A
GI-
115A
MC-
109A
SP-
87D
GI-
93C
SP-
89B
GI-
90A
ST-
81A
ST-
75JA(B)
ST-185B * * * * * * * * * * * *
GI-116A
* * * * * * * * * *
MC-311A * * * *
ST-185A * *
GI-94B *
ST-206A
GI-115A
MC-109A
SP-87D
GI-93C
SP-89B
GI-90A
ST-81A
ST-75JA(B)
61
980
981
982
983
984
121
122
... O&G infrastructure and operations have both negative and positive effects on marine ecosystems (Burdon et al., 2018). Negative impacts can include facilitating the establishment and spread of nonnative species (Page et al., 2019;Sammarco et al., 2014), disturbing habitats (Järnegren et al., 2017;Jones et al., 2006), introducing artificial lights and noise that alter species behaviour (Barker & Cowan, 2018;Montevecchi, 2006;Todd, Lazar, et al., 2020), introducing contaminants and nutrients (Adewole et al., 2010;Breuer et al., 2008;Henry et al., 2018;MacIntosh et al., 2021), and interfering with hydrodynamic processes and sedimentation patterns (Gray & Elliott, 2009). On the positive side, the presence of O&G infrastructure, particularly in oligotrophic environments or on seabeds where natural hard substrata are scarce, provides a physical structure for marine ecosystems to develop. ...
... Once colonised by non-native species, platforms can act as a source for non-native larvae, often to colonise wide geographical areas, depending on the species larval duration (Page et al., 2019;Simons et al., 2016). For example, corals from the genus Tubastraea are non-native species that are now widely distributed throughout the western Atlantic Ocean (Sammarco et al., 2012(Sammarco et al., , 2014 and are also present in the eastern Atlantic Ocean (Mantelatto et al., 2020). ...
... This genus does not compete well in its natural habitat, but the presence of O&G platforms allows successful settlement of their nonnative larvae in new areas and expansion of their distribution range (Sammarco et al., 2012(Sammarco et al., , 2014. O&G infrastructure and associated ship traffic have contributed to their spread, and they have now ...
Article
Full-text available
Offshore platforms, subsea pipelines, wells and related fixed structures supporting the oil and gas (O&G) industry are prevalent in oceans across the globe, with many approaching the end of their operational life and requiring decommissioning. Although structures can possess high ecological diversity and productivity, information on how they interact with broader ecological processes remains unclear. Here, we review the current state of knowledge on the role of O&G infrastructure in maintaining, altering or enhancing ecological connectivity with natural marine habitats. There is a paucity of studies on the subject with only 33 papers specifically targeting connectivity and O&G structures, although other studies provide important related information. Evidence for O&G structures facilitating vertical and horizontal seascape connectivity exists for larvae and mobile adult invertebrates, fish and megafauna; including threatened and commercially important species. The degree to which these structures represent a beneficial or detrimental net impact remains unclear, is complex and ultimately needs more research to determine the extent to which natural connectivity networks are conserved, enhanced or disrupted. We discuss the potential impacts of different decommissioning approaches on seascape connectivity and identify, through expert elicitation, critical knowledge gaps that, if addressed, may further inform decision making for the life cycle of O&G infrastructure, with relevance for other industries (e.g. renewables). The most highly ranked critical knowledge gap was a need to understand how O&G structures modify and influence the movement patterns of mobile species and dispersal stages of sessile marine species. Understanding how different decommissioning options affect species survival and movement was also highly ranked, as was understanding the extent to which O&G structures contribute to extending species distributions by providing rest stops, foraging habitat, and stepping stones. These questions could be addressed with further dedicated studies of animal movement in relation to structures using telemetry, molecular techniques and movement models. Our review and these priority questions provide a roadmap for advancing research needed to support evidence‐based decision making for decommissioning O&G infrastructure. Offshore platforms and related fixed structures supporting the oil and gas (O&G) industry are prevalent in all oceans. We review current knowledge on the role of O&G infrastructure in maintaining, altering or enhancing ecological seascape connectivity. There is a paucity of studies assessing connectivity and O&G structures. We discuss existing knowledge and identify critical knowledge gaps for decision‐making, such as the need to understand how O&G structures modify and influence movement patterns of mobile species and dispersal. Our review and priority questions provide a roadmap for advancing research needed to support evidence‐based decision‐making for decommissioning O&G infrastructure.
... Of these, T. coccinea and T. tagusensis are considered highly invasive NNS and cause significant environmental, economic, and social impacts as they spread in Brazil (Creed 2006, Lages et al. 2011, Mantelatto and Creed 2015. T. micranthus has a similar potential for negative impacts although less studied to date (Sammarco et al. 2010(Sammarco et al. , 2013(Sammarco et al. , 2014. Interestingly, T. coccinea and T. tagusensis co-occur in many areas, growing on top of each other and often coalescing (Creed et al. 2017b). ...
... The third species, T. micranthus, is thus far only found on oil and gas platforms operating in the (extra-tropical) northern GOM -with reports of colonies at depths ≤183 m (Sammarco et al. 2010(Sammarco et al. , 2013(Sammarco et al. , 2014. Interestingly, a fourth, yet unidentified clade of Tubastraea (with intermediate characteristics) has also been recognized in the GOM (Figueroa et al. 2019) and Brazil (Joel C. Creed, pers. ...
Article
Full-text available
Tropical marine ecosystems are biologically diverse and economically invaluable. However, they are severely threatened from impacts associated with climate change coupled with localized and regional stressors, such as pollution and overfishing. Non-native species (sometimes referred to as 'alien' species) are another major threat facing these ecosystems, although rarely discussed and overshadowed by the other stressors mentioned above. NNS can be introduced accidentally (for example via shipping activities) and/or sometimes intentionally (for aquaculture or by hobbyists). Understanding the extent of the impacts NNS have on native flora and fauna often remains challenging, along with ascertaining when the species in question actually became 'invasive'. Here we review the status of this threat across key tropical marine ecosystems such as coral reefs, algae meadows, mangroves, and seagrass beds. We aim to provide a baseline of where invasive NNS can be found, when they are thought to have been introduced and what impact they are thought to be having on the native ecosystems they now inhabit. In the appended material we provide a comprehensive list of NNS covering key groups such as macroalgae, sponges, seagrasses and mangroves, anthozoans, bryozoans, ascidians, fishes, and crustaceans.
... have been observed to grow on all kinds of artificial substrate, such as concrete (Ho et al., 2017) and plastics (Hoeksema and Hermanto, 2018;Valderrama Ballesteros et al., 2018;Faria and Kitahara, 2020), and in particular as invasive species on metal structures, such as ship hulls (Boschma, 1953), shipwrecks (Hoeksema et al., 2019b;Soares et al., 2020), pontoons (López et al., 2019;Tanasovici et al., 2020), and oil platforms (Brito et al., 2017;Creed et al., 2017). At Koh Tao, high abundances of Tubastraea micranthus were only found on the pinnacles, where they showed high abundances during the present study and earlier (Fig. 3;Valderrama Ballesteros et al., 2018), whereas the same species has been recorded as an invasive on oil rigs in the Gulf of Mexico (Sammarco et al., 2010(Sammarco et al., , 2014. The absence of Tubastraea on the artificial substrates around Koh Tao, cannot be explained by isolation because they are situated close to natural reefs and they have been in the water for many years. ...
Article
Concrete cubic frames and decommissioned steel naval vessels have been deployed in Thailand liberally to act as artificial substrates for coral restoration and marine recreation. We assessed recruitment at such substrate types at Koh Tao, Gulf of Thailand, and compared the community structure of scleractinian corals between artificial substrates and nearby natural reefs. Our results from a sample of 2677 recruits from nine sites highlighted significant differences in community structure between both reef types. Investigations of variables including time since deployment, distance from the natural reef, and seafloor depth revealed only the latter as a possible influencing factor. The diversity of recruits could not be explained by dynamics in coral spawning, and were found to represent groups with lower structural complexity. Our results suggest that coral community structure on artificial and natural reefs differs and supports distinct ecological and functional roles.
... O&G infrastructure has already initiated several species range extensions. Some of these species have gained pest status at their new location (Page et al., 2006;Sammarco et al., 2014;Tanasovici et al., 2020). Noting that current research on invasive species represents only 9% of biodiversity studies for in situ decommissioning research, a priority would be to investigate the propensity of invasive species to colonize subsea O&G structures. ...
Article
Full-text available
Numerous oil and gas (O&G) installations worldwide will need to be decommissioned in the near future. Complete removal of subsea structures is often the default approach although some regions retain structures under rigs-to-reefs programs. Here, we reviewed the published literature to understand the status of global research on decommissioning, and specifically identify gaps in ecological knowledge. We estimated the frequency of different research categories (i.e., themes, and spatial/temporal scales), and tested the assumption that the number of papers across the categories of each research aspect was even in distribution. However, the frequency of studies focusing on biodiversity at a local (≤100 km2) scale (relative to regional and oceanic and pan-oceanic scales) were significantly higher; while other theme categories (e.g., eco-toxicology, connectivity, structural-integrity, restoration and other) were significantly lower than expected. Temporally, ≤1-year studies were more frequent than multi-year studies, but these frequencies did not significantly deviate from the assumed distribution of equal frequencies. We propose that further research be carried out to evaluate the benefits of both retention and removal of structures. Ecological research on decommissioning should extend its focus beyond biodiversity, to include eco-toxicology, structural-integrity, connectivity at larger spatial and temporal scales. This would provide a more holistic assessment of ecological impacts to inform sustainable and equitable development choices in multiple Blue Economy sectors, as we transition from offshore O&G to marine renewables.
... It now has a pantropical distribution and is considered the most abundant scleractinian species in both the tropical Pacific and Atlantic (Cairns, 1994). A second species, the green cup coral Tubastrea micranthus, was first detected in 2006 on a single platform (GI-93-B) off the coast of Louisiana (Sammarco et al., 2010), but had appeared on eight additional platforms within a 20 mile radius of GI-93-B by 2014 (Sammarco et al., 2014b). The two species show clear depth preferences: whereas T. coccinea is generally found above 78 m, T. micranthus occupies deeper portions of the platforms, down to 138 m (Sammarco et al., 2013). ...
Article
Full-text available
The northern Gulf of Mexico has been an important source for crude oil and natural gas extraction since the 1930s. Thousands of fixed platforms and associated equipment have been installed on the Gulf of Mexico continental shelf, leading to a pervasive ‘ocean sprawl.’ After decommissioning, 100s of these structures have been converted to artificial reefs under the federal ‘Rigs-to-Reefs’ program, in addition to artificial reefs specifically designed to enhance fisheries and/or benefit the recreational diving industry. Apart from a few natural banks, which reach to approximately 55 ft below the surface, artificial reefs provide the only shallow-water hard substrate for benthic organisms in the deeper waters of the northern Gulf of Mexico. This vast expansion in available habitat has almost exclusively occurred over a relatively short span of time (∼50 years). The ecological interactions of artificial and natural reefs in the northern Gulf of Mexico are complex. Artificial reefs in general, and oil and gas structures in particular, have often been invoked as stepping stones for non-native and invasive species (e.g., Tubastrea cup corals, lionfish). The pilings are covered with fouling communities which remain largely unstudied. While the risks of these fouling organisms for invading natural reefs are being broadly discussed, other impacts on the ecological and economic health of the Gulf of Mexico, such as the potential to facilitate jellyfish blooms or increase the incidence of ciguatera fish poisoning, have received less attention. Artificial reefs also provide ecosystem services, particularly as habitat for economically important fish species like red snapper. Here we revisit the potential role of artificial reefs as ‘stepping stones’ for species invasions and for fisheries enhancement. Beyond concerns about ecological effects, some of these topics also raise public health concerns. We point out gaps in current knowledge and propose future research directions.
... In the American Atlantic tropical shores three Tubastraea species are currently recognized, which are believed to have been introduced in the 1940s from the Indo-Pacific (Cairns, 2000(Cairns, , 2001Creed et al., 2017). Two of these species, T. tagusensis and T. coccinea, are deemed to be powerful invasive species (Riul et al., 2013;Silva et al., 2014;Miranda et al., 2016;Creed et al., 2017), but the third one, T. micranthus (Ehrenberg, 1834), is also currently spreading (Sammarco et al., 2014Creed et al., 2017). The Tubastraea species recorded in this study also showed high dispersion abilities, with specimens widely distributed along the Santa Cruz de Tenerife harbor. ...
Article
In this study the presence, distribution and density of several species of Scleractinia corals introduced in the Canary Islands and settled in artificial substrata (marina pontoons and port docks) of the Santa Cruz de Tenerife harbor were studied. Tubastraea spp. and Oculina patagonica densities in such locations were assessed owing to their potential as invasive species, and the abundance of other introduced and native corals was also estimated. O. patagonica showed a high frequency of occurrence (28.8%), reaching densities of 0.25 colonies/m² and was exclusively located in the marina pontoons, found opposite the anchoring spots of oil platforms, mainly in shaded environments. Tubastraea spp. were also found in said area, where they showed very high densities (44.6% of frequency and 2.0 colonies/m²) regardless of light availability, as well as in the inner wall of another port dock where oil platforms berth. Other species were only recorded in the pontoon areas of the marina, with the occurrence of the Culicia genus especially remarkable (15.9%), whose only previous record in the Atlantic was in the Cape of Good Hope (South Africa). Tubastraea tagusensis was also recorded for the first time in the eastern Atlantic. Results confirm that oil platforms have been the introductory vector of non-native corals and the introduction process, the expansion and invasion risks, as well as the need for a control plan are discussed.
... A second invasive species of this genus, Tubastraea micranthus (Ehrenberg, 1834), was discovered in 2006 in the northern GOM (Sammarco et al. 2010). It is not as widespread as T. coccninea, but there are indications that it is expanding at a considerable rate in the northern GOM (Sammarco et al. 2014). The expanding populations of these two invasive species are of great concern because of their potential for spreading from predominantly artificial habitats to natural reefs and banks. ...
Article
Full-text available
Our research presents the first record of Tubastraea tagusensis (Wells, Notes on Indo-Pacific scleractinian corals. Part 9. New corals from the Galápagos Islands, 1982) in the Gulf of Mexico. Specimens of Tubastraea were collected from various artificial reefs. Morphological analyses of these specimens show that there are three distinct lineages of Tubastraea that have remained cryptic due to similar morphology in the field: Tubastraea coccinea (Lesson, 1829), T. tagusensis, and a third clade containing a mix of characters of the former two. These results based on morphology are corroborated by phylogenetic and haplotype analyses using a partial sequence of the mitochondrial genes ATP8 and cytochrome oxidase I (mtCOI). The negative effects on natural habitats by invasive species of Tubastraea have been documented worldwide. Therefore, it is imperative to implement management policies that will help prevent the expansion of these species into natural habitats in the Gulf of Mexico. The essential first step is accurate identification to determine possible sources, vectors, and current expansion rates. We present a clear set of morphological characters and a genetic marker to help distinguish between these three cryptic lineages.
... Características morfológicas e comportamentais Tubastraea spp. -São considerados corais pétreos ou escleractínios (produtores de esqueleto calcário), ahermatípicos (não construtores de recifes) e azooxantelados (não dependentes de algas simbiontes para nutrição) (Cairns 2002 (Fenner, 2001;Sammarco et al., 2004Sammarco et al., , 2012Sammarco et al., , 2013Sammarco et al., , 2014Creed et al., 2017a). Assim, a principal forma de dispersão identificada é via bioincrustação nestas estruturas flutuantes de deslocamento lento, com uma estreita relação entre presença e dispersão de colônias de coral-sol com a presença destas estruturas. ...
Technical Report
Full-text available
Guia para o manejo de espécies exóticas invasoras em unidades de conservação federais, com o objetivo de suprir uma lacuna de informação e orientação para uma das ameaças mais significativas à diversidade biológica. O guia contém uma revisão da legislação, lista das espécies de maior potencial invasor e orientações técnicas para o manejo das EEI nas unidades de conservação brasileiras.
... In the American Atlantic tropical shores three Tubastraea species are currently recognized, which are believed to have been introduced in the 1940s from the Indo-Pacific (Cairns, 2000(Cairns, , 2001Creed et al., 2017). Two of these species, T. tagusensis and T. coccinea, are deemed to be powerful invasive species (Riul et al., 2013;Silva et al., 2014;Miranda et al., 2016;Creed et al., 2017), but the third one, T. micranthus (Ehrenberg, 1834), is also currently spreading (Sammarco et al., 2014Creed et al., 2017). The Tubastraea species recorded in this study also showed high dispersion abilities, with specimens widely distributed along the Santa Cruz de Tenerife harbor. ...
Article
Zooxanthellate zoantharians (Cnidaria: Anthozoa) are commonly found in tropical and subtropical marine regions around the world. However, due to the low genetic variability of commonly used DNA markers combined with high levels of intraspecific morphological variation, misidentifications and species synonyms are commonly found in the literature. In this study, zoantharians from the suborder Brachycnemina collected in the Macaronesia and Cape Verde ecoregions were studied combining morphological, molecular and ecological data, in order to comprehensively assess the species diversity of the region. Moreover, molecular analyses of endosymbiotic Symbiodiniaceae zooxanthellae were also performed to provide more information on each holobiont. Our integrative results demonstrate that Brachycnemina species diversity increases as seawater temperature rises toward the tropics with a total of nine species recorded: one from waters around northern Madeira, five in the Canary Islands and seven in the southernmost Cape Verde Archipelago. All species were seen to host either Symbiodiniaceae of the genera Symbiodinium (former Symbiodinium ‘Clade A’) or Cladocopium (former Symbiodinium ‘Clade C’). Moreover, this study records for the first time the presence of Palythoa grandis, P. aff. clavata, P. grandiflora, an unknown Zoanthus species and Z. pulchellus in the East Atlantic Ocean. These results show no endemic zooxanthellate zoantharians in the East Atlantic, with all species shared with the West Atlantic.
Article
Full-text available
A great number of studies published on long-term ocean warming and increased acidification have forecasted changes in regional biodiversity preempted by aquatic invasive species (AIS). The present paper is focused on invasive Tubastraea coccinea (TC), an azooxanthellate AIS coral thriving in regions of the Gulf of Mexico, which has shown an ability to invade altered habitats, including endemic Indo-Pacific T. coccinea (TCP) populations. To determine if invasive TC are more stress resistant than endemic Indo-Pacific T. coccinea (TCP), authors measured tissue loss and heat shock protein 70 (HSP70) expression, using a full factorial design, post exposure to changes in pH (7.5 and 8.1) and heat stress (31 °C and 34 °C). Overall, the mean time required for TCP to reach 50% tissue loss (LD50) was less than observed for TC by a factor of 0.45 (p < 0.0003). Increasing temperature was found to be a significant main effect (p = 0.004), decreasing the LD50 by a factor of 0.58. Increasing acidity to pH 7.5 from 8.1 did not change the sensitivity of TC to temperature; however, TCP displayed increased sensitivity at 31 °C. Increases in the relative density of HSP70 (TC) were seen at all treatment levels. Hence, TC appears more robust compared to TCP and may emerge as a new dominant coral displacing endemic populations as a consequence of climate change.
Article
We review eight different pathways for invasion by aquatic species into Ontario. These include fish stocking programs, private aquaculture, bait industry, aquarium and ornamental pond industry, live food fish industry, recreational boating, canals and diversions, and commercial shipping. These pathways have been responsible for the introduction of more than 160 invasive aquatic organisms into Ontario. Due to several gaps in policy and legislation, we conclude that the greatest potential pathways for the future introduction and spread of invasive aquatic species are associated with ballast water from the shipping industry, the live food fish industry, and the ornamental pond/aquarium trade. We offer recommendations to reduce the potential for establishment of additional invasive aquatic species. New legislation is required and public awareness programs need to be expanded. Response protocols need to be developed which clearly define roles and responsibilities of different agencies. Finally, a more coordinated effort between stakeholders and various levels of government with regard to invasive aquatic species is needed.
Article
The reproductive ecology of Tubastraea coccinea Lesson, an azooxanthellate tropical scleractinian coral, was studied over various periods from 1985 to 2006 at four principal eastern Pacific locations in Costa Rica, Panama, and the Galapagos Islands (Ecuador). This small (polyp diameter 0.8–1.0 cm), relatively cryptic species produced ova and planulae year round, including colonies with as few as 2–10 polyps. Of 424 colonies examined histologically, 13.7% contained both ova and sperm. Mature ova varied in diameter from ∼300 to 800 μm and the time from spawning and fertilization of oocytes to release of brooded planulae was about 6 weeks. Planulae were 0.5–1.5 mm long and they settled and metamorphosed on a variety of substrates after 1–3 days. Spermaries, though more difficult to distinguish in histological sections, were present throughout the year. Spent spermaries were never observed in sections, but several colonies in Panama and the Galapagos Islands released sperm from night one to night five after full moon, indicating the potential for cross-fertilization among colonies. Planula release was observed at Uva Island (Panama) in March, May, June, and July, and in general planula presence was higher at warm ocean temperatures at all sites, whether or not the sites were influenced by seasonal upwelling. Annual fecundity estimates for T. coccinea are comparable with other high fecundity brooding species, including the zooxanthellate Porites panamensis, with which it co-occurs in Panama. Tubastraea coccinea is widely distributed in the tropical Indo-Pacific and has colonized substrates in the western Atlantic. In addition to the reproductive characteristics described in the present study, other features of the biology of T. coccinea, such as an ability to withstand conditions that produce bleaching and mortality in zooxanthellate species, may account for its widespread, low-latitude distribution in multiple oceans.
Article
The genus Tubastraea, with natural occurrence in the Pacific Ocean, was reported for the first time in Brazil along the coast of Rio de Janeiro. Since then it has also been reported in other sites along the south and southeast Brazilian coasts in oil platforms and rocky shores. We describe for the first time the occurrence of Tubastraea tagusensis and T. coccinea in the Northeastern coast of Brazil. The corals were found in the state of Bahia, sitting on shipwrecks, marina jetties as well as occupying space on a coral reef.
Article
The large, green, branching macroalga Codium fragile (Suringar) Hariot 1889 (Chlorophyta: Codiaceae) is one of the most abundant and widespread species in the morphologically and taxonomically diverse genus of Codium. Six distinct subspecies of C. fragile have been recognized, in addition to morphologically heterogeneous populations (with no subspecific name) on temperate and boreal shores throughout the world. Three of the subspecies appear to occur primarily as introduced forms: ssp. atlanticum and ssp. tomentosoides originated from Japan and ssp. scandinavicum originated from Siberia. Ssp. tomentosoides is one of the most invasive seaweeds in the world, with extensive transoceanic and interoceanic spread this century; the alga is a serious ecological and economic pest on NW Atlantic shores. Despite the high abundance and broad distribution of C. fragile, a disproportionate amount of study has focused on ssp. tomentosoides, in a narrow part of its invaded range, namely NW Atlantic shores; results from this region are not necessarily applicable to the alga in other temperate and boreal regions. Furthermore, much of the work on ssp. tomentosoides is unrelated to the invasion ecology of this alga, and many authors remain unaware of its exotic origins. In this review, I examine the ecological differences among and within subspecies and evaluate their relative invasiveness. Variation among subspecies of C. fragile occurs in the following attributes: (a) sexual reproduction v. parthenogenesis, (b) apparent ploidy level of the macroscopic adult thallus, (c) salinity tolerance, and (d) thallus buoyancy in terms both of tissue density and propensity to trap gases. There is little reported evidence, however, that subspecies vary substantially in length of their reproductive period, growth, phenology, vegetative propagation, physiological ecology, herbivore palatability, competitive ability, host epiphyte interactions, or natural products production. Comparative studies are needed to understand the variable invasiveness of the three introduced subspecies and the non-invasiveness of indigenous forms as well as geographic variation in ecological attributes of ssp. tomentosoides.