59,133 research outputs found
Movements and spawning of white marlin (Tetrapturus albidus) and blue marlin (Makaira nigricans) off Punta Cana, Dominican Republic
With a focus on white marlin (Tetrapturus albidus), a concurrent electronic tagging and larval sampling effort was conducted in the vicinity of Mona Passage (off southeast Hispaniola), Dominican Republic, during April and May 2003. Objectives were 1) to characterize the horizontal and vertical movement of adults captured from the area by using pop-up satellite archival tags (PSATs); and 2) by
means of larval sampling, to investigate whether fish were reproducing. Trolling from a sportfishing vessel yielded eight adult white marlin and one blue marlin (Makaira nigricans); PSAT tags were deployed on all but one of these individuals. The exception was a female white marlin that
was unsuitable for tagging because of injury; the reproductive state of its ovaries was examined histologically. Seven of the PSATs reported data summaries for water depth, temperature, and light levels measured every minute for periods ranging from 28 to 40 days. Displacement of marlin from the location of release to the point of tag pop-up ranged from 3l.6 to 267.7 nautical miles (nmi) and a mean displacement was 3.4 nmi per day for
white marlin. White and blue marlin mean daily displacements appeared constrained compared to the results
of other marlin PSAT tagging studies. White marlin ovarian sections contained postovulatory follicles and final maturation-stage oocytes, which indicated recent and imminent spawning. Neuston tows (n=23) yielded 18
istiophorid larvae: eight were white marlin, four were blue marlin, and six could not be identified to species. We speculate that the constrained movement patterns of adults may be linked to reproductive activity for both marlin species, and, if true, these movement patterns may have
several implications for management. Protection of the potentially important white marlin spawning ground near Mona Passage seems warranted, at least until further studies can be conducted on the temporal and spatial
extent of reproduction and associated adult movement
Transboundary Movement of Atlantic Istiophorid Billfishes Among International and U.S. Domestic Management Areas Inferred from Mark-Recapture Studies
Billfish movements relative to the International Commission for the Conservation of Atlantic Tunas management areas, as well as U.S. domestic data collection areas within the western North Atlantic basin, were investigated with mark-recapture data from 769 blue marlin, Makaira nigricans, 961 white marlin, Tetrapturus albidus, and 1,801 sailfish, Istiophorus platypterus. Linear displacement between release and recapture locations ranged from zero (all species) to 15,744 km (mean 575, median 119, SE 44) for blue marlin, 6,523 km (mean 719, median 216, SE 33) for white marlin, and 3,845 km (mean 294, median 98, SE 13) for
sailfish. In total, 2,824 (80.0%) billfish were recaptured in the same management area of release. Days at liberty ranged from zero (all species) to 4,591 (mean 619, median
409, SE 24) for blue marlin, 5,488 (mean 692, median 448, SE 22) for white marlin, and 6,568 (mean 404, median 320, SE 11) for sailfish. The proportions (per species) of visits were highest in the Caribbean area for blue marlin and white marlin, and the Florida East Coast area for sailfish. Blue marlin and sailfish were nearly identical
when comparing the percent of individuals vs. the number of areas visited. Overall, white marlin visited more areas than either blue marlin or sailfish. Seasonality was
evident for all species, with overall results generally reflecting the efforts of the catch and release recreational fishing sector, particularly in the western North Atlantic. This information may be practical in reducing the uncertainties in billfish stock assessments
and may offer valuable insight into management consideration of time-area closure regulations to reduce bycatch mortality of Atlantic billfishes
Population characteristics and biology of striped marlin, Tetrapturus audax in the New Zealand fishery : a thesis presented in partial fulfillment of the requirements for the degree of Master of Science (MSc) in Physiology at Massey University, Palmerston North, New Zealand
Striped marlin (Tetrapturus audax) are apex predators in the pelagic ecosystem and are seasonally abundant in the off-shore waters of New Zealand during December through May. Data presented in this thesis were derived from a variety of fishing databases from New Zealand, Australia and United States as well as biological samples collected from east Northland New Zealand. This thesis may be used to help answer questions about growth and size structure, factors influencing conventional tag recoveries, and the trophic dynamics of striped marlin in the New Zealand fishery. Results show that the average weight of striped marlin in the New Zealand recreational fishery has declined between 1925-1944 (117.9 ± 0.6 kg) and 1985-2003 (96.6 ± 0.3 kg) (Means ± S.E.). The root causes of this average size decline are unknown but appear to be related to the expansion of a surface longline fishery in the southwest Pacific Ocean during 1958. Despite the large average size (104.9 ± 0.2 kg) of striped marlin from New Zealand, parameters estimated in the von Bertalanffy growth model (L∞3010 mm, K=0.22 annual and t 0=-0.04) do not show higher growth rates compared to Hawaii or Mexico. During their residency in the New Zealand Exclusive Economic Zone (EEZ) the condition Wr (relative weight) of striped marlin improves from 95.1 ± 1.2 to 109.4 ± 3.4 and average weight increases from 98.1 ± 2.0 kg to 114.6 = 0.4 kg. These data imply that striped marlin migrate to New Zealand in order to take advantage of the abundant food resources and to improve condition after spawning in warmer waters to the north. Arrow squid (Nototodarus spp.), jack mackerel (Trachurus murphyi) and saury (Scomberesox saurus) comprised a large portion of the diet from (n=20) striped marlin stomachs during March of 2004. Additionally, with a consumption rate of 0.962 to 1.28 kg of prey per day, striped marlin may consume the equivalent of 2.8-3.5% of New Zealand's current commercial catch of arrow squid and jack mackerel respectively. With concerns about declining pelagic fish stocks, tag-and-recovery programmes have become increasingly popular and over 50% of recreationally captured marlin in New Zealand are tagged and released annually. However, low tag recovery rates (<1.0%) have hindered progress in understanding growth, stock structure and migration patterns important for managing this species. Data from this study suggests that tag returns from striped marlin would increase if more fish were captured and released in less than 39 min and a greater number of small (< 89 kg) individuals were released. Tag recoveries and presumably post-release survivorship of striped marlin was reduced by increasing capture time and fish size. Rates of injury were lowest during capture times ranging from 20-29 min and in fish weighing 60-89 kg
Life after Catch and Release
Since 1988 regulations have required U.S. longline fishermen to release all Atlantic white marlin, Tetrapturus albidus. By the late 1990’s, approximately 99% of Atlantic white marlin caught by U.S. recreational fishermen were released. Recent studies using PSAT technology indicate
that not all released fish survive and that a minor change in hook type, 0–5° offset circle hooks rather than straight-shank “J” hooks, may have a profound effect on post release mortality. Beginning in 2004, sea turtle mitigation measures have required U.S. longline fishermen to use circle hooks. Estimates of total catch, releases, and post release mortality of Atlantic white marlin caught by U.S. recreational fishermen were made in order to evaluate the potential reduction in mortality that may be realized by requiring the use of circle hooks rather than straight-shank “J” hooks by U.S. recreational fishermen. These estimates were compared to estimates of Atlantic white
marlin caught by the U.S. longline fisher
Reproductive biology of blue marlin (Makaira nigricans) in the western Pacific Ocean
The reproductive biology
of blue marlin (Makaira nigricans)
was assessed from 1001 fish (ranging
from 121 to 275 cm in eye-to-fork
length; EFL) caught by Taiwanese
offshore longliners in the western
Pacific Ocean from September 2000
to December 2001 and from 843 gonad
samples from these fish, The overall
sex ratio of the catch was approximately
1:1 dur ing the sampling
period, but blue marlin are sexually
dimorphic; females are larger than
males. Reproductive activity (assessed
by histology), a gonadosomatic index,
and the distribution of oocyte diameters,
indicated that spawning occurred
predominantly from May to September.
The estimated sizes-at-maturity
(EFL50) were 179.76 ±1.01 cm (mean
±standard error) for females and 130
±1 cm EFL for males. Blue marlin are
multiple spawners and oocytes develop
asynchronously. The proportion of
mature females with ovaries containing
postovulatory follicles (0.41) and
hydrated oocytes (0.34) indicated that
the blue marlin spawned once every
2–3 days on average. Batch fecundity
(BF) for 26 females with the
most advanced oocytes (≥1000 μm),
but without postovulatory follicles,
ranged from 2.11 to 13.50 million
eggs (6.94 ± 0.54 million eggs). The
relationships between batch fecundity
(BF, in millions of eggs) and
EFL and round weight (RW, kg) were
BF = 3.29 × 10 –12 EFL5.31 (r2 = 0.70)
and BF = 1.59 × 10–3 RW 1.73 (r2= 0.67),
respectively. The parameters estimated
in this study are key information
for stock assessments of blue
marlin in the western Pacific Ocean
and will contribute to the conservation
and sustainable yield o
Event Reconstruction with MarlinReco at the ILC
After an overview of the modular analysis and reconstruction framework Marlin
an introduction on the functionality of the Marlin-based reconstruction package
MarlinReco is given. This package includes a full set of modules for event
reconstruction based on the Particle Flow approach. The status of the software
is reviewed and recent results using this software package for event
reconstruction are presented.Comment: 6 pages, 2 .eps figures, to appear in Proc. LCWS06, Bangalore, March
200
Application of pop-up satellite archival tag technology to estimate postrelease survival of white marlin (Tetrapturus albidus) caught on circle and straight-shank (“J”) hooks in the western North Atlantic recreational fis
Short-duration (5- or 10-day) deployments of pop-up satellite archival tags were used to estimate survival of white marlin (Tetrapturus albidus) released from the western
North Atlantic recreational fishery. Forty-one tags, each recording temperature, pressure, and light level readings approximately every two minutes for 5-day tags (n= 5) or four minutes for 10-day tags (n= 36), were attached to white marlin caught with dead baits rigged on straight-shank
(“J”) hooks (n =21) or circle hooks (n=20) in offshore waters of the U.S. Mid-Atlantic region, the Dominican
Republic, Mexico, and Venezuela. Forty tags (97.8%) transmitted data to the satellites of the Argos system,
and 33 tags (82.5%) transmitted data consistent with survival of tagged animals over the deployment duration.
Approximately 61% (range: 19−95%) of all archived data were successfully recovered from each tag. Survival was
significantly (P<0.01) higher for white marlin caught on circle hooks (100%) than for those caught on straight-shank
(“J”) hooks (65%). Time-to-death ranged from 10 minutes to 64 hours following release for the seven documented mortalities, and five animals died within the first six hours after release. These results indicate that a simple change in hook type can significantly increase the survival
of white marlin released from recreational fi
Toward identification of larval sailfish (Istiophorus platypterus), white marlin (Tetrapturus albidus), and blue marlin (Makaira nigricans) in the western North Atlantic Ocean*
The identification of larval istiophorid billfishes from the western North Atlantic Ocean has long been problematic. In the present study, a molecular technique was used to positively identify 27 larval white marlin (Tetrapturus albidus), 96 larval blue marlin (Makaira nigricans), and 591
larval sailfish (Istiophorus platypterus) from the Straits of Florida and the Bahamas. Nine morphometric measurements were taken for a subset of larvae (species known), and lower
jaw pigment patterns were recorded on a grid. Canonical variates analysis (CVA) was used to reveal the extent
to which the combination of morphometric, pigment pattern, and month of capture information was diagnostic to species level. Linear regression revealed species-specific relationships between the ratio of snout length to eye orbit diameter and standard length (SL). Confidence limits about these relationships served as defining characters for sailfish >10 mm SL and for blue and white marlin >17 mm SL.
Pigment pattern analysis indicated that 40% of the preflexion blue marlin examined possessed a characteristic
lower jaw pigment pattern and that 62% of sailfish larvae were identifiable by lower jaw pigments alone. An identification key was constructed based on pigment patterns, month of capture, and relationships between SL and the ratio of snout length to eye orbit diameter. The key yielded identifications for 69.4% of 304 (blind
sample) larvae used to test it; only one of these identifications was incorrect. Of the 93 larvae that could not be identified by the key, 71 (76.3%) were correctly identified with CVA. Although identif ication of certain
larval specimens may always require molecular techniques, it is encouraging that the majority (92.4%) of istiophorid larvae examined were ultimately identifiable from external
characteristics alone
FISHING GROUND, CACTH COMPOSITION, HOOK RATE AND LENGTH DISTRIBUTION OF BILLFISHES CAUGHT BY TUNA LONG LINE IN INDIAN OCEAN
Billfishes area by cacth of tuna long line vessels in Indian Ocean. Billfish are consist of swordfish Xiphias gladius, black marlin Makaira indica, indo facific blue marlin Makaira mazara, stripe marlin Tetrapturus audax, indo facific sailfish Istiophorus platypterus and shortbill spearfish Tetrapturus angustirostris. Besides that, billfishes also have important economic value compared with tuna as an exsported species such as swordfish and marlin. To optimize the catch of billfishes in Indian Ocean, data and information of potential fishing ground, size and catch composition of this species are needed. The billfishes cacth composition collected in 2011 were dominated by 45% swordfish, 20% black marlin, 19% blue marlin,9% short bill spearfish, 6% sailfish and 1%stripe marlin. The billfishes size range which were caught between 60 - 280 cm LJFL (Lower Jaw Fork Length). The sword fish average length was 150 cm, blue marlin 197 cm, black Marlin 189 cm, sailfish 150cm ,short bill spearfish 144 cm and stripe marlin159 cm. From this observation, it was found that most of billfishes caught were in mature
Habitat Utilization and Dive Characterization of Blue Marlin (Makaira nigricans) and White Marlin (Kajikia albida) in the Western Atlantic Ocean
Blue marlin Makaira nigricans and white marlin Kajikia albida (formerly Tetrapturus albidus) are overfished in the Atlantic Ocean, with the vast majority of fishing mortality resulting from the pelagic longline fishery that targets tunas (Thunnus spp.) and swordfish Xiphias gladius. Time series of catch-per-unit-effort (CPUE) data have been fundamental to assessments of blue marlin and white marlin stocks, but these time series have been affected by a shift over time in pelagic longline fishing practices from shallow to deeper sets. One method for adjusting CPUE data for changes in fishing practices is a habitat-based standardization that modifies fishing effort in proportion to the vertical distribution of the species of interest and the fishing gear. For these models to be successfully applied to population assessments, the vertical habitat utilized by blue marlin and white marlin must be known. Pop-up satellite archival tags (PSATs) provide a means of collecting high resolution vertical movement and distribution data for billfishes.
In my study, 62 blue marlin and 40 white marlin were caught in recreational fisheries off the U.S. mid-Atlantic, Yucatan Peninsula, northern Caribbean, Venezuela, and Brazil, tagged with Microwave Telemetry, Inc. PTT-100 HR PSATs, and released. Data were recovered from PSATs attached to 57 surviving blue marlin and 36 surviving white marlin. PSATs successfully transmitted 18-100% of the data they recorded (mean 72%). The minimum 10-day displacements of both species averaged 242 km (range 9 to 942 km) and varied significantly between tagging locations, but not between species. Blue marlin spent a significantly higher (62%) amount of time in the upper 10 m of water than white marlin (56%). Both species spent greater than 95% of the time in water that was within 8o C of the sea surface temperature. Only 3.1% of white marlin demonstrated diel differences in the maximum depth of dives, while 29% of blue marlin dove into deeper waters during the day. Variables identified as explaining the most variation in dives were total dive duration, bottom time, ascent time, number of wiggles, wiggle depth, interdive interval, skew of ascent and descent, % time ascending, and % time descending. Using these variables, two dive types were identified through cluster analysis: simple dives representing traditional U and V shapes, and complex dives with multiple descents, plateaus, and wiggles. There were significant differences in dive variables among locations, individuals, diel periods, and dive types. There was significant overlap in range, habitat use, and vertical movement patterns, and therefore no strong evidence of niche partitioning between blue marlin and white marlin. My analyses can be used to further define the physical and physiological factors limiting marlins\u27 vertical movements and therefore improve stock assessments based on longline CPUE data by correcting for changes in fishing practices
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