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1.
《Rev Environmental Economics and Policy》2009,3(1):141-143
2.
《Rev Environmental Economics and Policy》2008,2(1):146-147
3.
《Rev Environmental Economics and Policy》2007,1(1):166-168
4.
Rafik Absi 《Environmental Fluid Mechanics》2008,8(4):389-394
In a recent paper published in this journal, Bonakdari et al. (Environ Fluid Mech 8:1–17, 2008) presented a new formulation
of the vertical velocity profile in the central portion of steady fully developed turbulent open-channel flows which is based
on an analysis of the Navier–Stokes equations. The predicted mean streamwise velocity profiles presented by the authors represent
dip phenomenon (maximum velocity below the free surface). The discusser would like to point out some contradictions and an
error in the main demonstration. This error appears in the right-hand side term of the main Eq. 22 (Environ Fluid Mech 8:1–17,
2008) in the parameter α. Our corrected demonstration shows that α is equal to and not to as obtained by the authors (Environ Fluid Mech 8:1–17, 2008). The values of α used by the authors are under-estimated by 1, this difference has a significant effect on velocities and therefore will involve
a difference between measured and predicted velocity profiles. Finally, the assumption of at the free surface is in contradiction with predicted velocity profiles. 相似文献
5.
Tomoharu Eguchi Jeffrey A. Seminoff Robin A. LeRoux Peter H. Dutton Donna L. Dutton 《Marine Biology》2010,157(8):1869-1877
Longitudinal capture-mark-recapture data were used to estimate abundance and survival rates for green turtles (Chelonia mydas) in San Diego Bay, California, USA. These turtles were closely associated with warm effluent from a power plant during winter
months. The life stage distribution of green turtles in the bay ranged from post-pelagic juveniles to adults (44.0–110.4 cm
straight carapace length). During 99 capture sessions between December 2, 1990, and March 25, 2009, 96 individual green turtles
were caught. To estimate abundance and survival rates, robust-design mark-recapture models were fitted to capture-recapture
histories using software MARK. The estimated annual survival rate was 0.861 (SE = 0.147, 95% CI = 0.356–0.986), whereas annual
abundance ranged from 16 (SE = 6.3, 95% CI = 4–29) to 61 (SE = 13.2, 95% CI = 36–88). This study provides the first survival
rate and abundance estimates for a green turtle foraging population in the highly industrialized San Diego Bay. 相似文献
6.
Seasonal aerial surveys were conducted in the waters of the central Spanish Mediterranean from 2001 to 2003 using the line transect sampling methodology to estimate cetacean abundance. The density of the three most abundant species, striped dolphin (Stenella coeruleoalba), bottlenose dolphin (Tursiops truncatus) and Risso’s dolphins (Grampus griseus), was estimated. In the case of the first two species, the density was estimated accounting for the proportion of submerged animals, while for Risso’s dolphin only the surface density could be estimated. The striped dolphin was the most abundant species in the study area with a mean density of 0.489 dolphins km−2 (95% CI = 0.339–0.705) and a mean abundance of 15,778 dolphins (95% CI = 10,940–22,756). This density is comparable to that obtained in the International Ligurian Sea Cetacean Sanctuary. Striped dolphins were observed throughout the whole year and no seasonal changes in the density were detected. The mean density of bottlenose dolphins was an order of magnitude lower than that of striped dolphins (0.041 dolphins km−2; 95% CI = 0.023–0.075) with a mean abundance of 1,333 dolphins (95% CI = 739–2,407). The Risso’s dolphin had a surface estimated density of 0.015 dolphins km−2 (95% CI = 0.005–0.046) and a mean abundance of 493 dolphins (95% CI = 162–1,498). These results provide valuable biological information useful to develop conservation plans and establish a baseline for future population trend studies. 相似文献
7.
Increasing threats to deep-sea corals highlight the need to expand knowledge of these taxa so that conservation measures can
be developed. The present study focused on the reproductive patterns of the deep-sea solitary coral Flabellum angulare. A series of samples (n = 398) collected in 2006–2008 in the northwest Atlantic at depths of 925–1,430 m revealed that gametogenesis was synchronous
among males and females and fluctuated seasonally. Initiation of gamete synthesis was estimated to be in August–September
and spawning in June. Further analysis and daily monitoring of 30–60 individuals maintained in a flow-through mesocosm showed
that gamete release occurred in March–June with a peak in May. Release of oocytes coincided with rising seawater temperatures
and high deposition rates indicative of elevated water column productivity. Oocytes (900–1,200 μm diameter) were released
through the oral cavity, generally in bundles of 3–5 surrounded by mesenterial filaments and attached to a thread (30–50 mm
long). As oocytes became free in the water column, ovulation occurred followed by fertilization. Eggs/embryos initially remained
on the tentacles of the spawner before either falling onto the substratum or floating to the surface. The embryos developed
into planula larvae measuring 2–3 mm in length within about 24 h. Together, these findings shed new light on the strategies
used by deep-sea corals to maximize their reproductive success. 相似文献
8.
Estimating abundance of killer whales in the nearshore waters of the Gulf of Alaska and Aleutian Islands using line-transect sampling 总被引:1,自引:0,他引:1
Alexandre N. Zerbini Janice M. Waite John W. Durban Rick LeDuc Marilyn E. Dahlheim Paul R. Wade 《Marine Biology》2007,150(5):1033-1045
Killer whale (Orcinus orca Linnaeus, 1758) abundance in the North Pacific is known only for a few populations for which extensive longitudinal data
are available, with little quantitative data from more remote regions. Line-transect ship surveys were conducted in July and
August of 2001–2003 in coastal waters of the western Gulf of Alaska and the Aleutian Islands. Conventional and Multiple Covariate
Distance Sampling methods were used to estimate the abundance of different killer whale ecotypes, which were distinguished
based upon morphological and genetic data. Abundance was calculated separately for two data sets that differed in the method
by which killer whale group size data were obtained. Initial group size (IGS) data corresponded to estimates of group size
at the time of first sighting, and post-encounter group size (PEGS) corresponded to estimates made after closely approaching
sighted groups. ‘Resident’-type (fish-eating) killer whales were more abundant than the ‘transient’-type (mammal-eating).
Abundance estimates of resident killer whales (991 [95% CI = 379–2,585] [IGS] and 1,587 [95% CI = 608–4,140] [PEGS]), were
at least four times greater than those of the transient killer whales (200 [95% CI = 81–488] [IGS] and 251 [95% CI = 97–644]
whales [PEGS]). The IGS estimate of abundance is preferred for resident killer whales because the estimate based on PEGS data
may show an upward bias. The PEGS estimate of abundance is likely more accurate for transients. Residents were most abundant
near Kodiak Island in the northern Gulf of Alaska, around Umnak and Unalaska Islands in the eastern Aleutians, and in Seguam
Pass in the central Aleutians. This ecotype was not observed between 156 and 164°W, south of the Alaska Peninsula. In contrast,
transient killer whale sightings were found at higher densities south of the Alaska Peninsula between the Shumagin Islands
and the eastern Aleutians. Only two sightings of ‘offshore’-type killer whales were recorded during the surveys, one northeast
of Unalaska Island and the other south of Kodiak Island. These are the first estimates of abundance of killer whale ecotypes
in the Aleutian Islands and Alaska Peninsula area and provide a baseline for quantifying the role of these top predators in
their ecosystem.
Electronic Supplementary Material Supplementary material is available in the online version of this article at and is accessible for authorized users.
相似文献
Alexandre N. ZerbiniEmail: |
9.
Eugene S. Morton Bridget J. M. Stutchbury Ioana Chiver 《Behavioral ecology and sociobiology》2010,64(6):947-954
We investigated sexual conflict over parental care in blue-headed vireos (Vireo solitarius) and documented the first example of unvarying unisexual brood desertion in passerines. Females at all nests (N = 24) that were monitored closely near fledgling, deserted their broods on or near the day of fledging leaving males alone
to complete parental care of young. No males deserted. This observational evidence was confirmed with radiotracking of females
(2004, 2007) and both pair members (2008). Radiotracked females began visiting distant males 1–4 days before young left the
nest, subsequently paired with males 355–802 m away, and laid first eggs in new nests less than 5 days after deserting. In
contrast, females suffering nest predation did not desert and renested with the same male. We suggest equal parental care
(nest building, incubation, feeding) in the sexes, genetic monogamy, and an adult sex ratio biased towards males has led to
female control of brood desertion in this species. Unisexual desertion may be more important in altricial birds than generally
realized and we discuss prerequisites to predict its occurrence. One is genetic monogamy, which may be a female tactic that
reduces the likelihood of males evolving counter-adaptations to female desertion. 相似文献
10.
A. Cornils S. B. Schnack-Schiel M. Böer M. Graeve U. Struck T. Al-Najjar C. Richter 《Marine Biology》2007,151(4):1261-1274
A total of 12 feeding experiments were conducted in the northern Gulf of Aqaba during spring (March/April) and autumn (September/October)
2002 at the Marine Science Station (MSS) in Aqaba. Females of three species of clausocalanids were selected: Clausocalanus
farrani, C. furcatus and Ctenocalanus vanus. Natural occurring particle (NOP) larger than 5 μm were investigated as food source. The ambient chlorophyll a concentration at sampling depth (∼70 m) ranged between 0.15 and 1.00 μg chl a l−1 and NOP concentrations ranged between 1.78 and 14.0 × 103 cells l−1 during the sampling periods. The division of particles into five size classes (5–10, 10–20, 20–50, 50–100 and >100 μm) revealed
that most of the particles were found in the size classes below 50 μm (81–98%), while most of the natural occurring carbon
(NOC) was concentrated in the size classes larger than 20 μm (70–95%). Ingestion rates were food density dependent rather
than size dependent ranging between 0.02 and 1.65 × 103 NOP ind−1 day−1 and 0.01 and 0.41 μg NOC ind−1 day−1, respectively, equivalent to a body carbon (BC) uptake between 0.4 and 51.8% BC day−1. The share of the size classes to the total ingestion resembled in most cases the size class composition of the natural particle
community. 相似文献
11.
12.
Wrasses are abundant reef fishes and the second most speciose marine fish family, yet little is known of their larval swimming
abilities. In August 2010 at Moorea, Society Islands, we measured swimming ability (critical speed, Ucrit) of 80 settlement-stage
larvae (11–17 mm) of 5 labrid species (Thalassoma quinquevittatum [n = 67], Novaculichthys taeniourus [n = 6], Coris aygula [n = 5], Halichoeres trimaculatus [n = 1] and H. hortulanus [n = 1]) and 33 new recruits of T. quinquevittatum. Median (mdn) larval Ucrit was 7.6–12.5 cm s−1. In T. quinquevittatum (n = 67), larvae of 12.5–14.5 mm swam faster (mdn 16.9 cm s−1) than smaller or larger larvae (mdn 3.9 and 3.2 cm s−1, respectively). Labrid larvae Ucrit is similar to that of other similar-sized tropical larvae, so labrids and species with
comparable settlement sizes should have similar abilities to influence dispersal. Ucrit of T. quinquevittatum recruits decreased to 47–56% of larval Ucrit in 2 days, implying rapid physiological changes at settlement. 相似文献
13.
The fate of 100 marked recruits of the rhizophytic alga Halimeda incrassata was followed in Puerto Morelos reef lagoon, Mexican Caribbean (20°52′N, 86°51′W), until death of the last individual from
April 2005–2007. Juvenile mortality was relatively high (19%), the half-life of adult thalli was 13 months and maximal lifespan
was 2 years. First age of sexual reproduction was 10 months, but only 6% of the marked thalli reproduced sexually. A subsequent
static life-table approach (February–April 2008) at two sites indicated low spatial variation in transition probabilities
between the life stages. Recruits were found throughout the year (density 2–11 thalli m−2) and were mostly of clonal origin. In a disturbed area, the density of sexual recruits was ~0.01 thalli m2. Temporal fluctuations in population size depended on mortality rates, which increased slightly after hurricanes Emily (July
2005) and Wilma (October 2005), but might otherwise be regulated by density-dependent processes. 相似文献
14.
Aaron D. Spares Michael J. W. Stokesbury Ron K. O’Dor Terry A. Dick 《Marine Biology》2012,159(8):1633-1646
The influence of salinity, temperature and prey availability on the marine migration of anadromous fishes was determined by describing the movements, habitat use and feeding behaviours of Arctic char (Salvelinus alpinus). The objectives were to determine whether char are restricted to the upper water column of the inter-/subtidal zones due to warmer temperatures. Twenty-seven char were tracked with acoustic temperature/pressure (depth) transmitters from June to September, 2008/2009, in inner Frobisher Bay, Canada. Most detections were in surface waters (0–3 m). Inter-/subtidal movements and consecutive repetitive dives (maximum 52.8 m) resulted in extreme body temperature shifts (−0.2–18.1 °C). Approximately half of intertidal and subtidal detections were between 9–13 °C and 1–3 °C, respectively. Stomach contents and deep diving suggested feeding in both inter-/subtidal zones. We suggest that char tolerate cold water at depth to capture prey in the subtidal zone, then seek warmer water to enhance feeding/digestion physiology. 相似文献
15.
The combined effects of ocean warming and acidification were compared in larvae from two populations of the cold-eurythermal
spider crab Hyas araneus, from one of its southernmost populations (around Helgoland, southern North Sea, 54°N, habitat temperature 3–18°C; collection:
January 2008, hatch: January–February 2008) and from one of its northernmost populations (Svalbard, North Atlantic, 79°N,
habitat temperature 0–6°C; collection: July 2008, hatch: February–April 2009). Larvae were exposed to temperatures of 3, 9
and 15°C combined with present-day normocapnic (380 ppm CO2) and projected future CO2 concentrations (710 and 3,000 ppm CO2). Calcium content of whole larvae was measured in freshly hatched Zoea I and after 3, 7 and 14 days during the Megalopa stage.
Significant differences between Helgoland and Svalbard Megalopae were observed at all investigated temperatures and CO2 conditions. Under 380 ppm CO2, the calcium content increased with rising temperature and age of the larvae. At 3 and 9°C, Helgoland Megalopae accumulated
more calcium than Svalbard Megalopae. Elevated CO2 levels, especially 3,000 ppm, caused a reduction in larval calcium contents at 3 and 9°C in both populations. This effect
set in early, at 710 ppm CO2 only in Svalbard Megalopae at 9°C. Furthermore, at 3 and 9°C Megalopae from Helgoland replenished their calcium content to
normocapnic levels and more rapidly than Svalbard Megalopae. However, Svalbard Megalopae displayed higher calcium contents
under 3,000 ppm CO2 at 15°C. The findings of a lower capacity for calcium incorporation in crab larvae living at the cold end of their distribution
range suggests that they might be more sensitive to ocean acidification than those in temperate regions. 相似文献
16.
Michael D. Arendt Albert L. Segars Julia I. Byrd Jessica Boynton Jeffrey A. Schwenter J. David Whitaker Lindsey Parker 《Marine Biology》2012,159(1):113-125
Sixteen satellite-tagged adult male loggerhead sea turtles (Caretta caretta) dispersed widely from an aggregation near Port Canaveral, Florida, USA (28°23′N, −80°32′W) after breeding. Northbound males
migrated further (990 ± 303 km) than southbound males (577 ± 168 km) and transited more rapidly (median initial dive duration = 6
(IQR = 4–16) versus 19 (IQR = 10–31) min, respectively).. Migration occurred along a depth corridor (20–40 m) except where
constricted by a narrow continental shelf width. Males foraged in areas 27 ± 41 km2 day−1 at locations <1–80 km from shore for 100.1 ± 60.6 days, with variability in foraging patterns not explained by turtle size
or geography. Post-breeding dispersal patterns were similar to patterns reported for adult female loggerhead sea turtles in
this region and adult male loggerhead sea turtles elsewhere in the northern hemisphere; however, foraging ground distributions
were most similar to adult female loggerhead sea turtles in this region. 相似文献
17.
Pistón M Silva J Pérez-Zambra R Dol I Knochen M 《Environmental geochemistry and health》2012,34(2):273-278
A multicommutated flow system was designed and evaluated for the determination of total arsenic and selenium by Hydride Generation
Atomic Absorption Spectrometry (HG-AAS). It was applied to the determination of arsenic and selenium in samples of natural
and drinking water. Detection limits were 0.46 and 0.08 μg l−1 for arsenic and selenium, respectively; sampling frequency was 120 samples h−1 for arsenic and 160 samples h−1 for selenium. Linear ranges found were 1.54–10 μg l−1 (R = 0.999) for arsenic and 0.27–27 μg l−1 (R = 0.999) for selenium. Accuracy was evaluated by spiking various water samples and using a reference material. Recoveries
were in the range 95–116%. Analytical precision (s
r
(%), n = 10) was 6% for both elements. Compared with the Standard Methods, APHA, 3114B manual method, the system consumes at least
10 times less sample per determination, and the quantities of acid and reducing agent used are significantly lower with a
reduction in the generation of pollutants and waste. As an additional advantage, the system is very fast, efficient and environmentally
friendly for monitoring total arsenic and selenium levels in waters. 相似文献
18.
A bottom-mounted upward-facing 38-kHz echo sounder was deployed at ~400 m and cabled to shore in Masfjorden (~60°52′N, ~5°24′E), Norway. The scattering layers seen during autumn (September–October) 2008 were identified by trawling. Glacier lanternfish
(Benthosema glaciale) were mainly distributed below ~200 m and displayed three different diel behavioral strategies: normal diel vertical migration
(NDVM), inverse DVM (IDVM) and no DVM (NoDVM). The IDVM group was the focus of this study. It consisted of 2-year and older
individuals migrating to ~200–270 m during the daytime, while descending back to deeper than ~270 m during the night. Stomach
content analysis revealed increased feeding during the daytime on overwintering Calanus sp. We conclude that visually searching glacier lanternfish performing IDVM benefit from the faint daytime light in mid-waters
when preying on overwintering Calanus sp. 相似文献
19.
The horned sea star (Protoreaster nodosus) is relatively common in the Indo-Pacific region, but there is little information about its biology. This study of the population
biology of P. nodosus was carried out in Davao Gulf, The Philippines (7°5′N, 125°45′E) between September 2006 and May 2008. Protoreaster nodosus was found in sand and seagrass dominated habitats at a mean density of 29 specimens per 100 m2 and a mean biomass of 7.4 kg per 100 m2, whereas a significantly lower density and biomass was found in coral and rock dominated habitats. Adult specimens (mean
radius R = 10.0 cm) were found at depths of 0–37 m, whereas juveniles (R < 8 cm) were only found in shallow sandy habitats with abundant seagrass (water depth ≤2 m). Increased gonad weights were
found from March to May (spawning period), which coincided with an increasing water temperature and a decreasing salinity.
Density and biomass did not change significantly during reproduction, but sea stars avoided intertidal habitats. All specimens
with R > 8 cm had well developed gonads and their sex ratio was 1:1. Protoreaster nodosus grew relatively slowly in an enclosure as described by the exponential function G = 7.433 e−0.257 × R
. Maturing specimens (R = 6–8 cm) were estimated to have an age of 2–3 years. Specimens with a radius of 10 cm (population mean) were calculated
to have an age of 5–6 years, while the maximum age (R = 14 cm) was estimated as 17 years. Potential effects of ornamental collection on the sea star populations are discussed.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
20.
Arthur R. Bos Girley S. Gumanao Marieke M. van Katwijk Benjamin Mueller Marjho M. Saceda Rosie Lynn P. Tejada 《Marine Biology》2011,158(3):639-648
Archaster typicus, a common sea star in Indo-Pacific regions, has been a target for the ornamental trade, even though little is known about
its population biology. Spatial and temporal patterns of abundance and size structure of A. typicus were studied in the Davao Gulf, the Philippines (125°42.7′E, 7°0.6′N), from February 2008 to December 2009. Specimens of
A. typicus were associated with intertidal mangrove prop roots, seagrass meadows, sandy beaches, and shoals. Among prop roots, specimens
were significantly smaller and had highest densities (131 ind. m−2) between November and March. High organic matter in sediment and a relatively low predation rate seemed to support juvenile
life among mangroves. Size and density analyses provided evidence that individuals gradually move to seagrass, sandy habitats,
and shoals as they age. Specimens were significantly larger at a shoal (maximum radius R = 81 mm). New recruits were found between August and November in both 2008 and 2009. Timing of recruitment and population
size frequencies confirmed a seasonal reproductive cycle. Juveniles had relatively high growth rates (2–7 mm month−1) and may reach an R of 20–25 mm after 1 year. Growth rates of larger specimens (R > 30 mm) were generally <2 mm month−1. The activity pattern of A. typicus was related to the tidal phase and not to time of day: Specimens moved over the sediment surface during low tides and were
burrowed during high tides possibly avoiding predation. This is one of the first studies to document an ontogenetic habitat
shift for sea stars and provides new biological information as a basis for management of harvested A. typicus populations. 相似文献