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A Perspective of the Importance of Artificial Habitat on the Management of Red Snapper in the Gulf of Mexico

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The Gulf of Mexico red snapper fishery has been declared as overfished, and overfishing is occurring. More stringent regulations, including reduced catch quotas and restrictions on the shrimp fishery to reduce bycatch of juvenile snappers, are anticipated. However, with projected rebuilding, maximum sustainable yield (MSY) is estimated to be between 11 and 25 million pounds. This exceeds previously recorded annual yields from U.S. Gulf waters. The fishery began during the mid 19th century off the northeastern Gulf coast, with harvests of only about 2 million pounds. Even at this rate, the stocks were depleted rapidly, and the fleets moved further south and east to find new sources. Numerous exploratory cruises to the western Gulf in the late 19th century found minimal snapper populations, but high concentrations discovered off Vera Cruz, Mexico, attracted fishers, and this area was the major source of snappers for more than a century. The deployment of petroleum structures in the mid 20th century in the western Gulf and thousands of artificial reefs in the north-central Gulf have markedly increased red snapper habitat in those areas. Currently, snapper populations around artificial reefs in the north-central and northwestern Gulf support the majority of the U.S. harvest. If habitat is limiting, the designations of “overfishing” and “overfished” may be misleading, and “unrealized harvest potential” may be a more accurate descriptor of the current status of the stock given the increased presence of additional habitat for red snapper. Decreases in these artificial structures (owing to natural degradation or removal) may decrease future harvest potential.
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A Prospective of the Importance of Artificial Habitat on the Management of Red
Snapper in the Gulf of Mexico
Robert L. Shipp a; Stephen A. Bortone b
a Department of Marine Sciences, University of South Alabama, Mobile, Alabama, USA b Minnesota Sea
Grant College Program, Duluth, Minnesota, USA
First Published on: 01 January 2009
To cite this Article Shipp, Robert L. and Bortone, Stephen A.(2009)'A Prospective of the Importance of Artificial Habitat on the
Management of Red Snapper in the Gulf of Mexico',Reviews in Fisheries Science,17:1,41 — 47
To link to this Article: DOI: 10.1080/10641260802104244
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Reviews in Fisheries Science
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ISSN: 1064-1262 print
DOI: 10.1080/10641260802104244
A Prospective of the Importance of
Artificial Habitat on the Management
of Red Snapper in the Gulf of Mexico
1Department of Marine Sciences, University of South Alabama, Mobile, Alabama, USA
2Minnesota Sea Grant College Program, Duluth, Minnesota, USA
The Gulf of Mexico red snapper fishery has been declared as overfished, and overfishing is occurring. More stringent
regulations, including reduced catch quotas and restrictions on the shrimp fishery to reduce bycatch of juvenile snappers,
are anticipated. However, with projected rebuilding, maximum sustainable yield (MSY) is estimated to be between 11 and
25 million pounds. This exceeds previously recorded annual yields from U.S. Gulf waters. The fishery began during the mid
19th century off the northeastern Gulf coast, with harvests of only about 2 million pounds. Even at this rate, the stocks
were depleted rapidly, and the fleets moved further south and east to find new sources. Numerous exploratory cruises to
the western Gulf in the late 19th century found minimal snapper populations, but high concentrations discovered off Vera
Cruz, Mexico, attracted fishers, and this area was the major source of snappers for more than a century. The deployment
of petroleum structures in the mid 20th century in the western Gulf and thousands of artificial reefs in the north-central
Gulf have markedly increased red snapper habitat in those areas. Currently, snapper populations around artificial reefs in
the north-central and northwestern Gulf support the majority of the U.S. harvest. If habitat is limiting, the designations of
“overfishing” and “overfished” may be misleading, and “unrealized harvest potential” may be a more accurate descriptor
of the current status of the stock given the increased presence of additional habitat for red snapper. Decreases in these
artificial structures (owing to natural degradation or removal) may decrease future harvest potential.
Keywords red snapper, artificial habitat, overfishing, management
Red snapper (Lutjanus campechanus) stocks in the Gulf of
Mexico (Gulf) have been declared overfished and overfishing
is occurring (SEDAR7, 2005). Currently, the Gulf of Mexico
Fishery Management Council (GMFMC) is in the 13th year of
a 29-year rebuilding plan designed to remove both designations
from this valuable resource. Although there are numerous reg-
ulations currently in place to aid in stock recovery, projections
are that recovery by the target date of 2032 may not occur unless
additional restrictions are imposed. An additional reduction in
the total allowable catch (TAC) is under consideration and will
impact the directed red snapper fishery. The TAC for the years
2001–2006 was set at 9.12 million pounds (mp) about equally di-
vided between recreational and commercial harvest. Additional
Address correspondence to Dr. Robert L. Shipp, Department of Marine
Sciences, University of South Alabama, Mobile, AL 36688, USA. E-mail:
reductions were imposed in 2007, reducing quotas to less than 6
million pounds. These have resulted in shorter seasons, smaller
bag and trip limits, and other related actions. In addition, there is
a high mortality of age 0 and 1 juvenile snapper caused by trawl
bycatch in the Gulf penaeid shrimp fishery. Thus, additional ac-
tions are under consideration to reduce bycatch, including areal
and seasonal shrimp fishery closures (GMFMP, 2006). These
suggested actions are being contemplated under the assumption
that the red snapper fishery is currently recruitment limited.
Model projections of maximum sustainable yield (MSY) for
Gulf red snapper stocks are between 11.3 and 25.4 mp annu-
ally (SEDAR7, 2005). These constitute a marked reduction in
hypothetical MSY from previous annual assessments. In earlier
assessments, some MSY projections ranged between 40 and 60
mp, and the 1999 stock assessment projected an MSY of 205
mp (GMFMC, 2004). The current smaller estimates reflect a
“more realistic” estimate of MSY, but they remain far in excess
of the actual historical landings for red snapper in the Gulf of
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Mexico. Although data from early years of the fishery are few
and often subjective, the highest landings before 1970 were ap-
proximately 9 mp, and, in most years, landings were about 5 mp.
Landings from the eastern Gulf of Mexico averaged more than
double those from the western Gulf until the late 1950s when
landings from both regions were similar until the mid 1960s,
from which time western Gulf landings began to exceed those
from the eastern Gulf and continue to do so (SEDAR, 2007;
This review briefly describes the history of the Gulf red snap-
per fishery and then describes the factors which may be responsi-
ble for the demographic changes in snapper stocks. These factors
likely explain the geographic shift in catches from the eastern
to the western Gulf. This has relevance to the management of
the stock and may result in changes in our understanding of the
stock’s limiting factors and model projections of stock charac-
The Gulf of Mexico red snapper fishery began in the mid
19th century off the Florida panhandle and Alabama coasts.
Until the availability of affordable ice (around 1869; Collins,
1887; Bortone et al., 1997), the fishery was limited to small
vessels from New England, known as “smacks” because their
live wells created a smacking sound of water (but, see Bor-
tone et al., 1997, wherein the term may be a phonetic spelling
of the Dutch name for these boats.) These vessels were lim-
ited to catches of 5,000 to 6,000 lb. With the availability
of ice, catches well in excess of 20,000 lb became possible,
as did longer voyages. The early history of the fishery, as
well as the status of the fishery to the mid 20th century has
been well documented by Camber (1955) and Bortone et al.
A more detailed and revealing review of the early fishery was
provided by Collins (1887) in a report to the U.S. Commission
of Fish and Fisheries. He reported that the specific area between
Mobile, Alabama, and Ft. Walton (then Camp Walton), Florida,
constituted the origin of the fishery. He further noted that stock
depletion was evident even in these early days of the fishery:
The character of the snapper grounds, so far as relates to abun-
dance of fish on them, and, of course, their consequence im-
portance, has changed very materially, it is said, within the past
three or four years.
It is claimed that this change is still going on, and that localities
that were remarkable for the abundance of fish on them only a
year or two ago are now of comparatively little importance. The
best evidence that can be adduced in support of this theory is the
fact that the vessels are continually obliged to extend further off
in order to meet with success, and at present we are told that it
would be of little use to attempt to catch fish on grounds where
they could be taken in great numbers in the early days of the
business (Collins 1887:281).
Collins also mentioned that total annual catches were about
Collins (1887) alludes to rumors about snapper stocks off
Campeche and Vera Cruz, Mexico, but this major source of
red snapper was unknown at this time. However, exploratory
voyages were being made in search of new red snapper grounds.
Particularly, the western Gulf received much exploratory effort
in the 1880s:
It may not be out of place to say that quite extended researches
have been made west of the Mississippi in search of snapper
banks, the demand for fish in the Galveston and New Orleans
markets, and the consequent high price often being paid, no
doubt, an inducement toward making these investigations. As
early as the fall of 1880, two smacks from Noank Conn., which
were fishing in the Gulf, made a cruise off Galveston in search of
fishing grounds, but found no bottom suitable for red snappers to
live on. Mr. Sewell C. Cobb also tells us that he spent the entire
month of July, in 1883, seeking for red snappers, and sounding
along the coast, from the southwest pass of the Mississippi to a
point off the center of Padre Island, Texas, a distance of about
450 miles. The bottom, over all this extent of ground, was mostly
mud and broken shells, and totally devoid of any fish life, as far
as he could tell.
In the summer of 1884 the Pensacola Ice Company sent another
schooner off Galveston for red snappers, but the voyage was a
failure, the vessel not getting enough fish to pay her provision
bill (Collins 1887:280).
Collins also noted that the catches were dominated by
relatively large fishes, often averaging ten pounds or more
(Figure 1).
Following the Collins (1887) review, additional reviews of
the snapper fishery in the 19th century were provided by Smith
(1895) and Warren (1898), both describing the large catches off
Campeche. During the early part of the 20th century, Jordan and
Evermann described the snapper fishery as follows: “Its centre
of abundance is in the Gulf of Mexico in rather deep water in
the rocky banks off the west coast of Florida and the coasts of
Campeche and Yucatan” (1923:410). Gowanloch described the
location of the snapper fishery: “The center of this fishery lies
east of Louisiana” (1933:193). But, perhaps the most compre-
hensive review of the first century of the fishery was contributed
by Camber (1955). While a detailed discussion of this work
is beyond the scope of this paper, Camber’s summary of the
fishery is extremely revealing. For example, there are five ref-
erences to the fishery off the west coast of Florida, seven to
the fleet fishing off Campeche, and not a single reference to
the north central Gulf west of Alabama and westward to Texas,
despite the fact that much of the fleet claimed Mobile, Alabama,
New Orleans, Louisiana, and Galveston, Texas, as their home
port. Camber does mention that “some of the larger vessels
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Figure 1 A late 19th century catch of red snapper landed at the port of Mobile, AL (USA Archives).
which normally fished Campeche occasionally also visited the
‘Galveston Lumps’. However, not many captains in Pensacola
and Mobile were familiar with that poorly charted area, and, un-
til depth recorders became available, the number of trips made
was small” (1955:48).
Camber provided a figure of the areas fished by the snapper
fleet during those first 100 years, and it includes an area from
the mouth of the Mississippi River westward to an area south
of Galveston, termed the “Western.” However, he made sparse
reference to this area, noting that it was “all points within 10
miles on both sides of the 100 fathom line, between latitude
29.20 and longitude 89.20 and 98.00” (Camber, 1955:13). In
addition, the Galveston snapper fleet was described in 1939 as
spending from 14 to 25 days at sea with boats that “frequently
sail to the Campeche shoals, although there was some hard
bottom as close as 30 miles from shore” (Camber, 1955).
The importance of the Campeche fishing ground is reflected
throughout the body of the Camber work and is summarized in
his Table 16. Red snapper catches from Campeche comprised
about 75% of the landings reported from Pensacola and about
50% of the landings reported from the Florida West Coast.
Thus, it appears that the major red snapper fishing grounds
from the industry’s inception in the mid 19th century until the
mid 20th century was off the west coast of Florida, the Florida
Panhandle, and the Campeche grounds, with relatively few land-
ings off Mississippi and westward and southward to the Texas-
Mexico border.
The SEDAR7 (2005) red snapper stock assessment chron-
icled the historical landings of the U. S. red snapper harvest
from U.S. Gulf waters from 1880 to 1970. These landings are
in agreement with the above review of the fishery. From 1880
to about 1950, the harvest was principally from the eastern Gulf
and Campeche. Total catch from these areas averaged about 3.5
mp annually, with a maximum annual catch of 6 mp around
1900. Catches during this period from the western Gulf were
generally less than 1 mp. Red snapper catch changed radically
in the 1950s, with the harvest from the western Gulf of Mexico
equaling that from the eastern Gulf during this decade. By 1970,
the red snapper catch from the western Gulf (about 5 mp) nearly
doubled that from the eastern Gulf (Figure 2). More recently, the
red snapper catch from the western Gulf is currently estimated
6 to 7 times greater than the catch from the eastern Gulf in terms
of virgin biomass (SEDAR 7, 2005; RW-4:3).
Interestingly, red snapper catches off Alabama have domi-
nated the recreational harvest in the Gulf, even though this area
represents less than 5% of the U.S. Gulf of Mexico continental
shelf. The recent catch of red snapper off Alabama represents
an estimated 40% of the total recreational catch from the Gulf
of Mexico (Figure 3), which is nearly equal to the total annual
catch of red snapper from the Gulf in the 1880s.
In 1947, “Block 32,” southeast of the northeast coast of
Texas brought in a gusher of oil, and the full-scale exploration
for petroleum in the northwestern Gulf of Mexico had begun
(Yergin, 1991). Over the next several decades, more than 4,000
platforms were deployed in the relatively shallow shelf area
of the region, markedly transforming the available habitat in
the Gulf (Figure 4). Currently, there are approximately 3,900
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Figure 2 Reconstructed landings of red snapper caught in the U.S. Gulf of Mexico (east or west of the Mississippi River) for the years 1880–2003. Arrowsconnect
trends with important historical events. Arrows from below are after Porch et al. (2004) (data 1880–1962), Poffenberger and Turner (2004) (data 1962–2003), and
arrow from above from Yergin (1991).
oil platforms still standing, with about an equal number (ap-
prox. 100) being constructed and decommissioned annually (R.
Kasperzak, Louisiana. Dept. of Wildlife and Fisheries, personal
communication). Wilson et al. (2006) detailed the value of oil
platforms as artificial reefs, concluding that they support fish
densities 10 to 1,000 times that of adjacent sand and mud bot-
tom, and almost always exceed fish densities found at both
adjacent artificial reefs and natural hard bottom.
Off Alabama, an artificial reef program was initiated in 1953
when the Orange Beach Charter Boat Association began de-
positing reef materials off that state’s coast. In 1974, retired
U.S. Navy “liberty ships” were deployed at five locations in
24–28 m of water. In 1987, the U.S. Army Corps of Engineers
issued a general permit to the Alabama Department of Conser-
vation for reef siting off the Alabama coast. This permit is still
extant and covers more than 1,200 square miles (3,108 km2)of
continental shelf bottom in depths of approximately 20–90 m.
Altogether, an estimated 20,000 artificial structures have been
placed in this area (MRD, 2006). Previous to this reef deploy-
ment activity, the permit area was primarily sandy mud with
Figure 3 Geographical distribution of average commercial, recreational, and total landings of red snapper caught in U.S. waters in the Gulf of Mexico for
harvest years 1999–2002 (National Marine Fisheries Service—MRFSS and Headboat Statistics and Texas Parks and Wildlife Recreational Survey Statistics).
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Figure 4 Cartoon representing recent (1990–2000) locations of operating petroleum rigs in the Gulf of Mexico (Minerals Management Service Statistics).
limited hard bottom, nearly all of which was of low relief and
dominated by diminutive fish species, chiefly sparids, serranids,
and pleuronectids of negligible economic value (Shipp, 1999).
Although the two habitat alterations described above are by
far the most extensive in the Gulf of Mexico, supplementary
additions of hard bottom through the permitted deployment of
artificial reefs, including oil drilling platforms, have occurred
in every Gulf state. While the fish demographic changes may
vary, each state has expanded its artificial reef program in recent
years, chiefly to enhance red snapper stocks (L. Simpson, Gulf
States Marine Fisheries Commission, personal communication).
The debate regarding the status of red snapper stocks in the
Gulf of Mexico is ongoing. Current models and assessments
indicate these stocks in the Gulf are overfished and that over-
fishing is occurring (SEDAR7, 2005). The assessment models
are based on the premise that red snapper stocks are recruit-
ment limited, but there remains considerable uncertainty in the
stock-recruit relationship. Of interest, the SEDAR7 (2005) re-
port concludes that, for more than a decade, recruitment levels
have been far greater than would be expected from the estimated
stock size. In fact, estimated recruitment since 1985 was, on av-
erage, higher than virgin recruitment despite the stock being
estimated as highly depleted.
The information presented above suggests that habitat may be
an important factor regulating stock size. Evidence indicates that
massive areas of the northern and northwestern Gulf of Mexico
were essentially depauperate of snapper stocks for the first 100
years of the fishery. Subsequently, areas in the western Gulf
have become the major source of red snapper, concurrent with
the appearance of thousands of petroleum platforms and other
artificial reef deployments. This information argues persuasively
for a reevaluation of the importance of habitat as a limiting factor
for red snapper. Similarly, addition of an extensive artificial reef
network on the near-shore continental shelf off Alabama has
transformed the area from a relatively unproductive area for red
snapper to one of the most productive red snapper areas in the
Gulf of Mexico. The hypothesis that red snapper are habitat
limited appears reasonable, especially if the alternative is to
accept the idea that a grossly depleted stock is producing higher
recruitment than the virgin stock.
When one discusses these habitat modifications, the issue of
attraction versus production is inevitably raised. One of us (RLS)
discussed this issue at length (Shipp, 1999), and contended that,
for the area off Alabama, an increase in total biomass was not
what was relevant. Rather, it was the transformation of the sub-
stratum from a predominantly sandy mud habitat to one having
increased areas of hard bottom with high relief that relieved the
“bottleneck” that had previously prevented red snapper from
increasing in abundance.
Osenberg et al. (2002) indicated that artificial reefs can offer
some species an opportunity for expansion if the artificial reef
provides a means for relief from a “bottleneck” on life-history
features. Bortone (2008) presented a model that explains the
advantage that artificial reefs may have in providing both attrac-
tion and production benefits to fishes that comprise demersal
fisheries like red snapper. Artificial reefs may attract fish but,
in addition, they may also provide increased habitat that re-
lieves a “bottleneck” in the life history that previously restricted
population abundance.
One may ask if it is simply a result of attraction, where are
the snappers attracted from? There are no areas of the Gulf that
have become less productive for red snapper in recent decades.
And, in fact, (1) recent landings data (1999–2002) from the
Florida west coast (Figure 3), when compared to landings data
(1995–1999) provided by Schirripa and Legault (1999); (2) tes-
timony by reputable commercial fishermen at GMFMC meet-
ings (March, 2006), and (3) testimony by a NMFS scientist at
the GMFMC meeting (November, 2006) using fishery indepen-
dent methods all support the view that red snapper stocks in
that area are increasing. In addition, mark-recapture data from
recent studies off Alabama (Watterson et al., 1998; Patterson
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et al., 2001) demonstrated a prevalent west to east movement of
red snappers from the Alabama area to the Florida panhandle
and beyond.
Further evidence for the habitat limitation hypothesis rather
than purely attraction was provided by Szedlmayer and Shipp
(1994). They demonstrated a marked increase in abundance of
early juvenile (age 0) red snapper within the Alabama artificial
reef permit area following large-scale reef placement. Thus,
the increased population in this area was likely attributable to a
habitat-related recruitment increase and not a result of migration
from other areas.
One might also contend that during the early red snapper fish-
ery in the Gulf of Mexico, the technology to locate additional
hard bottom and the unexploited stock was unavailable. Had
such technology existed, and had additional habitat been located,
the relatively small annual landings of around 2 mp at the fish-
ery’s inception would not have depleted the entire stock. How-
ever, the recent tag-recapture studies cited above also demon-
strate that red snapper stocks are redistributed during tropical cy-
clones. Data from 1872 to 1889 record landfall of 11 hurricanes
between Gulfport and Pensacola (Dr. A. Williams, Department
of Meteorology, University of South Alabama, personal com-
munication). This is the precise area of the fishery’s origins.
Thus, occurrences of these storms would have replenished red
snapper to the few known hard bottom areas from the more
extensive but uncharted surrounding areas, had they existed.
The massive additions of artificial reef habitat preferred by
red snapper during the last 50 years in the north-central and
northwestern Gulf of Mexico has corresponded with major shifts
in harvest locations and areas of red snapper concentrations. This
suggests that habitat was a factor that limited population abun-
dance during the first 100 years of the fishery. Current model
projections of MSY at levels higher than have ever been achieved
also suggest that increases in habitat have increased harvest po-
tential. However, because current models are premised on a
stock of red snapper that is recruitment limited, these stocks are
considered “overfished, and overfishing is occurring.” Consid-
eration of increased habitat would lead to a different conclusion
(i.e., the stocks have an unrealized harvest potential).
In addition, if the habitat limitation hypothesis is correct, it
will be necessary to maintain, or even increase the amount of
artificial habitat in the northern Gulf of Mexico to keep pace with
fishing pressure. Programs such as the “rigs to reefs” efforts off
Louisiana and Texas would have to be continued, as would the
reef construction off Alabama.
The authors thank Ms. Monica Powers for her efforts to locate
many of the historical documents cited in this paper.
Bortone. S. A., R. B. Besser, and C. R. McNeil. The Importance of
Silas Stearns (1859–1888) and the Pensacola Red Snapper Fishery
to North American Ichthyology. Collection Building in Ichthyology.
American Society of Ichthyologists and Herpetologists, pp. 459–467
Bortone, S. A. Coupling fisheries with ecology through marine artificial
reef deployments. Pages 917–924. In: J. Nielsen, J. J. Dodson, K.
Friedland, T. R. Hamon, J. Musick, and E. Verspoor (eds.). Recon-
ciling Fisheries with Conservation: Symposium 49. Proceedings of
the Fourth World Fisheries Congress. American Fisheries Society.
Bethesda, Maryland (2008).
Camber, C. I. A Survey of the Red Snapper Fishery of the Gulf of
Mexico, with Special Reference to the Campeche Banks. State of
Florida Board of Conservation Marine Laboratory, Technical Series
No. 12, Florida (1955).
Collins. J. W. Report on the discovery and investigation of fishing
grounds made by the Fish Commission steamer Albatross during a
cruise along the Atlantic Coast and in the Gulf of Mexico, with notes
on the Gulf fisheries. Report of the U.S. Commission of Fisheries,
13: 217–311 (1887).
GMFMC (Gulf of Mexico Fishery Management Council). Final
Amendment 22 to the Reef Fish Fishery Management Plan to Set
Red Snapper Sustainable Fisheries Act Targets and Thresholds, Set
a Rebuilding Plan, and Establish Bycatch Reporting Methodologies
for the Reef Fish Fishery. Gulf of Mexico Fishery Management
Council, Florida (2004).
GMFMP (Gulf of Mexico Fishery Management Plan). Scoping Docu-
ment for Amendment 27 to the Reef Fish FMP and for Amendments
14 and 15 to the Shrimp FMP. Gulf of Mexico Fishery Management
Council, Florida (2006).
Gowanloch, J. E. The red snapper, pp. 193–195. In: Fishes an d Fis h-
ing in Louisiana. State of Louisiana Department of Conservation,
Bulletin No. 23. New Orleans (1933).
Jordan, D. E., and B. W. Evermann.American Food and Game Fishes.
A Popular Account of all the Species Found in America North of
the Equator, with Keys for Ready Identification, Life Histories,
and Methods of Capture. New York: Dover Publications, 573 pp.
MRD (Marine Resources Division, Alabama Department of Conserva-
tion). Alabama’s Artificial Reefs. Alabama Department of Conser-
vation and Natural Resources, 15 pp. (2006).
Osenberg, C. W., C. M. St. Mary, J. A. Wilson, and W. J. Lindberg. A
quantitative framework to evaluate the attraction-production contro-
versy. ICES J. Mar. Sci., 59: S214–S221 (2002).
Patterson, W. F. III, J. C. Watterson, R. L. Shipp, and J. H. Cowan, Jr.
Movement of tagged red snapper in the northern Gulf of Mexico.
Trans. Am. Fish. Soc., 130: 533–545 (2001).
Poffenberger, J. R., and S. C. Turner. Documentation on the prepara-
tion of the database for the red snapper stock assessment SEDAR
workshop. SEDAR7-AW-17 rev. SEDAR, Charleston, SC (2004).
Porch, C. E., S. C. Turner, and M. J. Schirripa. The commercial landings
of red snapper in the Gulf of Mexico from 1872 to 1962. SEDAR7-
AW-22. SEDAR, Charleston, SC (2004).
Schirripa, M. J., and C. M. Legault. Status of the red snapper fishery in
the Gulf of Mexico: Updated through 1998. NMFS, Southeast Fish-
eries Science Center, Sustainable Fisheries Division Contribution:
SFD-99/00-75 (1999).
reviews in fisheries science vol. 17 1 2009
Downloaded By: [Gallaway, Benny] At: 20:08 24 February 2009
SEDAR7 (Southeast Data, Assessment, and Review). Stock assess-
ment report of SEDAR 7: Gulf of Mexico red snapper. SEDAR,
Charleston, SC (2005).
Shipp, R. L. The artificial reef debate: Are we asking the wrong ques-
tions? Gulf Mexico Sci.,17(1): 51–55 (1999).
Smith, H. M. Report of the division of statistics and method of the
fishing. Rpt. U.S. Comm. Fish.,19: 68–70. 1895.
Szedlmayer, S. T., and R. L. Shipp. Movement and growth of red snap-
per, Lutjanus campechanus, at artificial reef sites in the northeastern
Gulf of Mexico. Bull. Mar. Sci.,55: 887–896 (1994).
USA (University of South Alabama) Archives. University of South
Alabama, Mobile, AL .
Warren, A. F. The red snapper fisheries; their past, present, and future.
Bull. U.S. Fish. Comm., 17: 331–335 (1898).
Watterson, J. C., W. F. Patterson III, R. L. Shipp, and J. H. Cowan,
Jr. Movement of red snapper, Lutjanus campechanus, in the north
central Gulf of Mexico: Potential effects of hurricanes. Gulf Mexico
Sci., 1: 92–104. 1998.
Wilson, C. A., M. W. Miller, Y. C. Allen, K. M. Boswell, and D. L.
Nieland. Effects of depth, location, and habitat type on relative abun-
dance and species composition of fishes associated with petroleum
platforms and Sonnier Bank in the northern Gulf of Mexico. U.S.
Dept. of the Interior, Minerals Management Service, Gulf of Mex-
ico OCS Region, New Orleans, LA. OCS Study MMS 2006-037. 85
pp. (2006).
Yergin, D. The Prize: The Epic Quest for Oil, Money, and Power. New
York: Simon and Schuster, 877 pp. (1991).
reviews in fisheries science vol. 17 1 2009
Downloaded By: [Gallaway, Benny] At: 20:08 24 February 2009
... Prior reviews on connectivity between natural and artificial reefs in the nGoM were generally focused on particular taxonomic groups, such as corals (e.g., Sammarco et al., 2004) or commercially important fish (e.g., Shipp and Bortone, 2009;Cowan et al., 2011). This review has a wider taxonomic scope and broader view of ecological implications, in particular highlighting emerging concerns for which we lack sufficient knowledge. ...
... The primary argument in favor of artificial reefs is the enhancement of fisheries, including the recovery of overfished populations (Pickering and Whitmarsh, 1997;Shipp and Bortone, 2009;Bull and Love, 2019). There are two competing hypotheses about the role of artificial reefs for fish stocks (Bohnsack and Sutherland, 1985;Bohnsack, 1989;Pickering and Whitmarsh, 1997): the production hypothesis states that artificial structures increase fish stocks in an ecosystem by providing additional shelter and food, while the attraction hypothesis posits that artificial structures attract fish from nearby areas by providing shelter and food, thus only leading to a redistribution of the existing fish stock. ...
... The red snapper (Lutjanus campechanus) fishery, dating back to the mid 1800s, is one of the most important in the GoM, and its history has been reviewed in several recent publications (Shipp and Bortone, 2009;Cowan et al., 2011;Bull and Love, 2019). Other commonly fished species associated with artificial reefs in the nGoM are gray snapper (a.k.a. ...
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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 United States territorial waters of the Gulf of Mexico, over 20,000 known (and innumerable unofficial and uncounted) artificial structures have been created in the last half century (Shipp and Bortone, 2009;Schulze et al., 2020). The proliferation of artificial structures has been driven by expansive reef building and enhancement programs, which have been used as de facto management tools aimed at rebuilding the resource (Shipp and Bortone, 2009;Cowan et al., 2011). ...
... In the United States territorial waters of the Gulf of Mexico, over 20,000 known (and innumerable unofficial and uncounted) artificial structures have been created in the last half century (Shipp and Bortone, 2009;Schulze et al., 2020). The proliferation of artificial structures has been driven by expansive reef building and enhancement programs, which have been used as de facto management tools aimed at rebuilding the resource (Shipp and Bortone, 2009;Cowan et al., 2011). However, a fundamental, and largely still unanswered, question associated with artificial structures is whether they serve as focal points for fishing mortality (i.e., attraction of effort) or if they actually increase recruitment by providing additional settlement habitat (i.e., increased production), thereby allowing for increased fishing opportunities (Bohnsack, 1989;Bortone, 1998;Cowan et al., 2011). ...
... Historically, the large-scale distribution of fishing effort is well documented, with commercial fishing being concentrated on large-scale natural features in the late 19th and early 20th centuries. In the latter half of the 20th century, both commercial and recreational fisheries shifted towards artificial structures as reef building programs proliferated (Shipp and Bortone, 2009). However, to date, there has been no systematic and high-resolution mapping of fishery removals by reef type. ...
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Marine artificial structures provide important ecosystem benefits, but the extent to which commercially valuable reef fish species and their associated fisheries utilize artificial structures is still undetermined. However, the increasing implementation of onboard Vessel Monitoring Systems (VMS) now enables precise identification of catch and effort locations that can be linked via satellite coordinates to seafloor habitat maps. To better understand the distribution of fishing effort across artificial and natural reef types in the Gulf of Mexico, we present the first attempt to link VMS data from commercial reef fish vessels with high resolution habitat maps for an iconic species, red snapper (Lutjanus campechanus). By allocating landings from VMS-linked individual fishing trips to habitat type (i.e., natural reef, artificial structure, or uncharacterized bottom) and overlaying these with previously developed red snapper biomass distributions, we are able to develop one of the first fine-scale spatial maps of exploitation across the entire Gulf of Mexico. Results indicated that nearly half (46%) of commercial red snapper landings were extracted from artificial structures. The degree of exploitation was highly heterogeneous with several localized hotspots on natural reefs along the continental shelf break and offshore areas of the Northeast Gulf of Mexico. Similarly, there were distinct regional differences in fishing patterns: a majority of the landings from the state of Florida (~91%) came from natural reefs, whereas ~75% of landings were from artificial structures from all other Gulf of Mexico states combined. These results indicate that the potential for localized depletion exists for red snapper. The exploitation maps developed here can directly aid fisheries managers by highlighting specific habitats and locations that should be carefully monitored as catch limits continue to increase.
... In support of the production hypothesis, some studies such as Brickhill et al. (2005), Karnauskas et al. (2017), Gallaway et al. (2018), and Szedlmayer and Bortone (2020) reported that artificial reefs may act as nursery areas for juvenile or subadults of some important commercially or recreationally harvested species (e.g., red snapper, Lutjanus campechanus), but until recently there have been few studies that have indicated whether artificial reefs potentially increase the local biomass of benthic invertebrates and fishes (but see Powers et al. 2003, Shipp and Bortone 2009, Fowler and Booth 2012, Syc and Szedlmayer 2012, Folpp et al. 2020). The question is further complicated given that it suspected that densitydependent changes to demographic parameters regulating populations may occur for some species as a consequence of individuals becoming concentrated on artificial reefs . ...
... Given most artificial reefs will likely remain on the seabed once decommissioned, it will be important to ensure that they are made from materials that, once eroded, do not threaten marine ecosystems. Here it is worth noting the special case of oil rigs, which although not specifically designed to be fish habitat have become key hard bottom to some fisheries, such as for red snapper (Lutjanus campechanus) in the Gulf of Mexico (Shipp andBortone 2009, Gallaway et al. 2019); however, only 1266 oil rigs, from a peak of about 4000, remain in the Gulf of Mexico due to removal of these structures on decommissioning. In many parts of the world there is now an emphasis on leaving some rigs in situ because of the known benefits to fisheries (e.g., Ajemian et al. 2015). ...
Artificial reefs have many applications but are best known for their deployments to enhance recreational fisheries by creating new habitat in areas where natural reef is otherwise limited. The expectation is that fish assemblages will take up residence on artificial reefs and that these assemblages will become at least similar, if not more diverse and abundant, to those on natural reefs. Although designed, purpose-built artificial reefs are becoming more widely used in support of recreational fisheries and many of the historic issues have been resolved, conservation practitioners and managers still face challenges as to the type, number, and arrangement of structures and where to deploy them to maximize benefits and minimize risks. The ecological literature was reviewed to develop and enhance contemporary principles of artificial reef best practices for utilization. Our review identified optimal shapes, vertical relief, void spaces, and unit arrangements for increasing volumes and diversity of catch to recreational fishers and we provide a tool for identifying the least constrained areas for artificial reef deployment. We suggest; (a) monitoring of noncatch motivators in combination with quantitative indicators of the fishing activity (e.g., catch rate and effort) will provide the best understanding of success or failure of an artificial reef deployment; (b) choosing target species for informing purpose-built artificial reef designs to be reef-associated, demersal, philopatric, territorial, and obligatory reef species that are desired by local recreational fishers; and (c) considering the ecosystem services provided by artificial reefs beyond those associated with recreational fishing.
... The Red Snapper Lutjanus campechanus is a reefassociated species found throughout the Gulf of Mexico (GOM; NOAA 2019) that relies on hard substrate for its habitat (Patterson et al. 2001;Ajemian et al. 2015). However, the majority of the GOM is comprised mostly of mud bottom (Shipp and Bortone 2009); therefore, Red Snapper exploit artificial structures for habitat (Downey et al. 2018). Oil and gas exploration in the GOM and the subsequent construction of platforms for oil and gas extraction beginning in the 1980s have provided structurally complex havens for these fish (Downey et al. 2018). ...
... Density assessments performed by Patterson et al. (2005) found that Red Snapper numbers were greatest in habitats that provide centimeters to meters of structure. Additionally, the creation of reefs from decommissioned platforms (i.e., rigs-to-reef structures [hereafter, "rigs-toreefs"]), wrecks, and reef balls provides additional habitat for Red Snapper (Shipp and Bortone 2009;Syc and Szedlmayer 2012;Ajemian et al. 2015). ...
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The Red Snapper Lutjanus campechanus is a reef‐associated species found throughout the Gulf of Mexico that relies on artificial structures for habitat. In this study, we used Bayesian models to determine habitat selection by different sizes and ages of female Red Snapper and to identify whether there was a difference in habitat selection between immature and mature fish. Red Snapper (n = 693) were sampled using vertical longlines from March or April through November of 2016–2018 off the coast of Mississippi at different artificial structure types (platforms, artificial reefs, and rigs‐to‐reef structures [hereafter, “rigs‐to‐reefs”]) and depths (shallow, <20 m; mid‐depth, 20–49 m; and deep, 50–100 m). To adjust for the traditional occurrence of mature fish being larger and older than immature fish, only fish within the intersection of the FL (n = 616) and age (n = 622) ranges of immature and mature classes were used in these analyses. Fork length and age of immature and mature fish increased with increasing depth, but immature fish had a larger increase in FL per unit depth than mature fish. Immature fish on artificial reefs were found to be older than immature fish at platforms, while there was no age difference between the two structures for mature fish. There was no difference in FL or age between rigs‐to‐reefs and platforms or artificial reefs for immature fish, but FL and age of mature fish were greater at rigs‐to‐reefs than at platforms and artificial reefs. However, maturity did not play a role in how age increased with depth or with differences in FL between artificial reefs and platforms for mature fish. These differences in habitat use based on maturity should be considered along with FL and age to inform management regulations for Red Snapper.
... For the highly-exploited red snapper, it is critical to understand the environmental factors that shape their abundance and distribution due to the long history of overfishing, the continued rebuilding status of the stock, and widespread debate over the management of the fishery Shipp and Bortone 2009;SEDAR 2018). Given the significant investment in understanding red snapper population dynamics, it is also important to identify understudied regions and the key environmental and ecological drivers of red snapper abundance within the GOM so that future research effort may be directed toward the areas of greatest need. ...
... The high study effort on the influence of habitat type and habitat complexity on the abundance of red snapper is not surprising, given that the GOM contains the largest artificial reef complex in the world (Dauterive 2000), particularly if the thousands of offshore petroleum platforms, pipelines, and related structures are included. There is growing support for the idea that artificial reefs and platforms can enhance red snapper populations in the GOM by increasing the area of suitable habitat, prey resources, and shelter (Shipp and Bortone 2009;Syc and Szedlmayer 2012;Brandt and Jackson 2013;Streich et al. 2017;Karnauskas et al. 2017); however, several studies contend that fish are merely attracted to artificial reefs (Cowan et al. 1999;Patterson and Cowan 2003). While artificial reefs comprise only a small fraction of available high-relief habitats, the current fishery relies heavily on catches of young adults (2-3 years) from artificial reefs, suggesting that increases in the number of artificial reefs are linked to production increases (Shipp 1999;Szedlmayer 2007;Gallaway et al. 2009). ...
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We conducted a meta-analysis to summarize current knowledge on the effects of environmental and ecological drivers on the abundance of red snapper (Lutjanus campechanus) within the U.S. Gulf of Mexico. We reviewed 1252 published research articles and extracted or calculated effect sizes for 12 drivers from 82 independent studies within 26 articles that met our inclusion criteria. We used a fixed-effect model to calculate the absolute value of the mean effect size of each driver by age class studied and pooled across age classes to estimate effects on the overall abundance of red snapper. Habitat complexity and intra-specific competition had large effects on overall abundance and juvenile abundance, while habitat type and protection from predators showed medium to large effects on age 0 recruits and juvenile red snapper, and the mean effect of all drivers studied for adult red snapper were small or had no effect on abundance. Our results provide systematic support for the role of density-dependent mechanisms (habitat quality and availability, competition, predation) in shaping the regional abundance of red snapper, particularly during the juvenile stages. Sensitivity analyses indicated that issues with non-independence (e.g. within-article correlation), between-study heterogeneity, and publication bias influenced the magnitude and certainty of effect size estimates in a subset of drivers. Thus, our meta-analytical review also highlights the need for more empirical research on certain drivers (e.g. temperature, hypoxia) to improve our understanding of the factors that shape the regional abundance of red snapper.
... In contrast, the value of these platforms to the Red Snapper fishery is much less contentious. In areas of the Gulf of Mexico where platforms (and other artificial reefs) are present, a large but unquantified portion of the Red Snapper landings come from these habitats (Gallaway et al. 2009;Shipp and Bortone 2009;Karnauskas et al. 2017). Karnauskas et al. (2017) noted that for younger year-classes, catch rates on artificial structures were 20 times higher than on natural reefs. ...
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Offshore petroleum platforms provide habitat that is utilized by an array of reef fish that are valuable to both commercial and recreational fishers. However, thousands of offshore platforms have been decommissioned in the Gulf of Mexico over the past decade, with many of the removals being accomplished using explosive severance methods. Here, we estimate the impact of platform removal in the Gulf of Mexico on five stocks of federally‐managed reef fish based on the percentage of each stock that is resident on platforms. We conclude that the gulf‐wide impact of removal will be relatively minor (1 to 8% of the estimated stock abundance) for four species, Red Snapper Lutjanus campechanus, Gray Triggerfish Balistes capriscus, Vermilion Snapper Rhomboplites aurorubens and Cobia Rachycentron canadum. In contrast, losses for the Greater Amberjack Seriola dumerili stock would potentially represent 45% of the known stock. An alternative explanation is that the actual abundance of Greater Amberjack is much larger than the most recent stock‐size estimate; in either case, we suggest this issue needs further examination. Removal impacts could also be significant for reef‐fish fisheries (especially the Red Snapper fishery) in areas where platforms are presently abundant but other high‐relief natural or artificial reefs are not present. Removal of the platforms from these areas will greatly impact the local fisheries.
... Management of the species began in 1984 (Goodyear, 1995), and has led to a recent increase in stocks, with commercial and domestic landings for the GOM in 2020 equal to the set annual catch limit of 15.1 million pounds (NOAA, 2020). The most recent stock assessment found that Red Snapper Snapper (Shipp and Bortone, 2009). Mississippi waters contain 82 artificial reefs, 8 rigs-to-reefs and 172 standing oil platforms within 32 km of shore (T. ...
Red Snapper (Lutjanus campechanus) is a popular reef-associated fish species in the northern Gulf of Mexico (GOM) that supports both commercial and recreational fisheries. In this region, there is a large overlap in fork length (FL, 90%) and age (93%) range between mature and immature females. Therefore, here we investigate how age and FL of mature and immature female Red Snapper vary by artificial reef type and depth. Red Snapper (n = 695) were sampled using vertical long lines from March or April through November of 2016 – 2018 off the coast of Mississippi at different artificial structure types (platforms, artificial reefs, rigs-to-reefs) and depths (shallow, < 20 m; mid, 20-49 m; deep, 50-100 m). To investigate habitat use of mature and immature fish respectively, we developed linear mixed-effects models. For both immature and mature fish, FL and age increased significantly with depth. Immature fish captured at artificial reefs were older than those captured at platforms, and mature fish were older and had longer FL at rigs-to-reefs than platforms and artificial reefs. The effect of depth on FL or age did not differ between mature and immature fish while the effect of structure types did. First, structure types were important to predict FL for mature fish, but not for immature fish. In addition, the differences in age between rigs-to-reefs and both platforms and artificial reefs were significantly larger in mature fish than in immature fish. Larger and older mature females are found at deeper depths where fishing pressure is lower, while smaller and younger, immature fish are most often found in shallower, reef-based areas where pressure is highest. These spatial differences in maturity can help inform management regulations for the species.
... Overall, Red Snapper are most abundant in the GOM in areas with the most oil and gas platforms and ARs (Gallaway et al. 2009), although historical catches indicate that Red Snapper were abundant in both the eastern and western GOM prior to the proliferation of artificial structures (Fitzhugh et al. 2020). The addition of AR structure to undifferentiated bottom in Alabama (USA) state waters transformed that region from one of low incidence to one of the highest for GOM Red Snapper (Shipp and Bortone 2009). Off the coasts of Texas and Louisiana, Red Snapper are most abundant on structures in depths ranging from 50 to 90 m, but off the coasts of Alabama and Florida they are more common in AR zones in a variety of depths (Karnauskas et al. 2017). ...
Red Snapper Lutjanus campecheanus is a structure‐associated species occurring across a wide depth range in the northern Gulf of Mexico. We used the random forest machine learning algorithm to understand which habitat and individual fish characteristics could predict reproductive parameters of female Red Snapper. We evaluated fish captured from 2016‐2018 on three artificial reef types with various structure heights at depths < 100 m. Overall, we found that depth and month were important predictors for most reproductive parameters, but the type of structure (artificial reef, oil platform, and “rigs‐to‐reefs”) was not important. Maturity was correctly classified in 88.9% of the cases when using the random forest ensemble model, with important predictors including fork length (FL), depth, structure height, and month of collection. Spawning seasonality (measured as GSI) was correctly classified in 59.5% of the cases when using histology reproductive phase, FL, month, and depth variables. Reproductively active or inactive females are correctly classified in 89.3% of the cases using GSI, month, FL and depth, while females in the developing vs. spawning capable phases were correctly classified in 82.2% of the cases using GSI, FL, month and depth. Histological indicators that show potential spawning within a 36 h period were correctly classified 61.5% of the time, with the best predictors being depth, FL, GSI, and month. Stepwise regression using AIC indicated that only the factor month significantly predicted contrasts in relative batch fecundity, with significantly greater values in August compared to all other months. Our findings suggest that female Red Snapper reproductive effort is not consistently or well predicted by artificial structure type or height, but that a combination of fish fork length, month and depth can predict reproductive characteristics of female Red Snapper.
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This book has one chapter in aquaculture development and 8 chapters in the global fisheries management. Aquaculture chapter describes how to use orange and potato peels as fish feed material. Fisheries chapters include the use of tax to manage a multigear fishery , Pan-Arctic fisheries, trawl selectivity, oil and gas platforms vs. fish and fisheries, Brown Seaweeds fishery, Blue Swimming Crab fishery, SUISAN fisheries education in Japan, and Carangids taxonomy in Pakistan.
Technical Report
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Herein, is a narrative report describing assemblage characterization of fishes at study area platforms based on the results from field season 2 (Milestone 6 of Contract No. M16PC00005).
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Site fidelity and movement of red snapper, Lutjanus campechanus, were estimated from a tagging study conducted off the coast of Alabama from March 1995 to January 1997. Red snapper were caught using rod and reel over nine artificial reef sites, with three reefs each located at 21-m, 27-m, and 32-m depths. During the study, 1,604 fish were tagged, and 174 recaptures were made of 167 individuals. On 4 October 1995, the eye of Hurricane Opal passed within 40 km of the artificial reef sites. When recaptures were stratified according to whether or not they were at liberty during Opal, storm effect was the most significant factor in predicting the likelihood of movement and magnitude of movement by tagged red snapper. Eighty percent of recaptured red snapper that were not at liberty during Opal were recaptured at their site of release. Fish that were at liberty during Opal, however, had a significantly higher likelihood of movement away from their site of release (P < 0.001). These fish also moved significantly further than those that were not at liberty during Opal (P < 0.001). Fish that were at liberty during Opal moved a mean distance(± SE) of 32.6 km(± 6.81), compared to a mean distance (± SE) of 2.5 km (± 1.10) for fish that were tagged and recaptured before Opal, and a mean distance (± SE) of 1.7 km(± 0.43) for fish that were tagged and recaptured after Opal. Heretofore, it has generally been accepted that adult red snapper demonstrate strong site fidelity and genetic homogeneity in the stock was hypothesized to result from larval drift or due to historic mixing on longer time scales. This study documents movement of adult red snapper on spatial scales that would facilitate stock mixing and implicates large-scale climatic events, such as hurricanes, as important factors in stock mixing dynamics.
Beneath the coastal waters of the world lie thousands of artificial reefs. Some are old and retired freighters and ships that once plied the oceans of the world but now serve as habitats for marine life. Others are newer reefs that have been designed and built for specific applications. With the field of aquatic habitat technology continually growing, this book responds to the global need for a compendium of consistent and reliable practices with which to evaluate how well artificial reefs meet their objectives. Artificial Reef Evaluation With Application to Natural Marine Habitats is a comprehensive guide to the methods used to document the performance of artificial reefs in coastal and oceanic waters. It is the first volume to combine the essential disciplines required for proper evaluation, including engineering, economics, biology, and statistics. This work covers the design of reef studies, multi-disciplinary methods of investigation, data analysis, and examples of applying the methods to reefs built for different purposes. Further, the methods examined in this book apply to other benthic marine habitats, such as coral reefs or “live bottoms”, thus expanding the book’s relevance to a wider audience and enhancing research efforts in the field of artificial habitat technology.
Artificial reefs have been proposed as a tool to mitigate impacts on natural reefs, augment natural fish production, and divert detrimental harvesting activities from sensitive natural habitats. The efficacy of this strategy depends on the extent to which artificial reefs contribute to new production or simply redistribute fish during or after settlement. Small coral reef fishes are ideal study subjects because redistribution is most likely during the larval stage, given limited dispersal of benthic stages. We develop a model that incorporates the simultaneous effects of habitat augmentation, competition among reefs for larval settlers, and post-settlement density-dependence, and propose two experimental approaches for evaluating the effects of artificial reefs on local production of natural reefs. One is based on small-scale studies using replicated patch reefs, the other on unreplicated studies using larger reefs and the Before-After-Control-Impact Paired Series (BACIPS) design. Using field data for six fish species, we estimated spatial and temporal variance and thus statistical power of both designs. Power varied among species, but in most cases was sufficiently high to detect local reductions in density of 10–40% with modest levels of replication (6–20 patch reefs or sampling dates). Copyright 2002 International Council for the Exploration of the Sea. Published by Elsevier Science Ltd. All rights reserved.