排序方式: 共有25条查询结果,搜索用时 31 毫秒
1.
Carlos Carroll Brett Hartl Gretchen T. Goldman Daniel J. Rohlf Adrian Treves Jeremy T. Kerr Euan G. Ritchie Richard T. Kingsford Katherine E. Gibbs Martine Maron James E. M. Watson 《Conservation biology》2017,31(5):967-975
Government agencies faced with politically controversial decisions often discount or ignore scientific information, whether from agency staff or nongovernmental scientists. Recent developments in scientific integrity (the ability to perform, use, communicate, and publish science free from censorship or political interference) in Canada, Australia, and the United States demonstrate a similar trajectory. A perceived increase in scientific‐integrity abuses provokes concerted pressure by the scientific community, leading to efforts to improve scientific‐integrity protections under a new administration. However, protections are often inconsistently applied and are at risk of reversal under administrations publicly hostile to evidence‐based policy. We compared recent challenges to scientific integrity to determine what aspects of scientific input into conservation policy are most at risk of political distortion and what can be done to strengthen safeguards against such abuses. To ensure the integrity of outbound communications from government scientists to the public, we suggest governments strengthen scientific integrity policies, include scientists’ right to speak freely in collective‐bargaining agreements, guarantee public access to scientific information, and strengthen agency culture supporting scientific integrity. To ensure the transparency and integrity with which information from nongovernmental scientists (e.g., submitted comments or formal policy reviews) informs the policy process, we suggest governments broaden the scope of independent reviews, ensure greater diversity of expert input and transparency regarding conflicts of interest, require a substantive response to input from agencies, and engage proactively with scientific societies. For their part, scientists and scientific societies have a responsibility to engage with the public to affirm that science is a crucial resource for developing evidence‐based policy and regulations in the public interest. 相似文献
2.
Use of otoliths and eye lenses for measuring trace-metal incorporation in fishes: a biogeographic study 总被引:1,自引:0,他引:1
The otoliths and lenses of the temperate damselfish Parma microlepis (Günther) (Pomacentridae) showed similar differences in trace-metal profile for selected locations along the coast of New
South Wales, Australia. Otoliths and lenses displayed a differential ability to accumulate metals. Metal concentrations were
ranked differently in the two structures (e.g. Sr > Ba > Pb > Rb > Hg in otoliths, and Hg > Sr ≃ Rb > Pb > Ba in lenses),
and where similar metals were accumulated, they were accumulated at vastly different concentrations (e.g. Ba concentrations
in otoliths are a thousand-fold greater than in lenses). Analyses of the otoliths and lenses of P. microlepis from locations close to Sydney and up to 100 km from the city were able to distinguish amongst these locations with respect
to a number of metals, namely Ba, Mn and Hg. Multivariate analyses of otolith and lens data gave similar results among locations
(agreement was obtained for 11 out of 15 pair-wise comparisons), and differences were attributable to the differential ability
of the two structures to accumulate metals such as Mn and Hg. Trace-metal differences between locations were found to coincide
with the proximity of sewage (including industrial waste) and petroleum storage facilities to the different locations.
Received: 23 June 1997 / Accepted: 4 August 1997 相似文献
3.
Andrea Gori Sergio Rossi Cristina Linares Elisa Berganzo Covadonga Orejas Mark RT Dale Josep-Maria Gili 《Marine Biology》2011,158(8):1721-1732
In the Western Mediterranean Sea, the gorgonian Eunicella singularis (Esper, 1794) is found at high densities on sublittoral bottoms at depths from 10 to 70 m. Shallow colonies have symbiotic
zooxanthellae that deeper colonies lack. While knowledge of the ecology of the shallow populations has increased during the
last decades, there is almost no information on the ecology of the deep sublittoral populations. In October and November 2004
at Cap de Creus (42°19′12″ N; 03°19′34″ E), an analysis of video transects made by a remotely operated vehicle showed that
shallow populations (10–25 m depth) were dominated by small, non-reproductive colonies, while deep sublittoral populations
(50–67 m depth) were dominated by medium-sized colonies. Average and maximum colony heights were greater in the deeper populations,
with these deeper populations also forming larger patch sizes and more extensive regions of continuous substrate coverage.
These results suggest that shallow habitats are suitable for E. singularis, as shown by the high recruitment rate, but perturbations may limit or delay the development of these populations into a
mature stage. This contrasts with the deep sublittoral habitats where higher environmental stability may allow the development
of mature populations dominated by larger, sexually mature colonies. 相似文献
4.
The surface slicks of internal waves were sampled in continental shelf waters off the east coast of Northland, New Zealand, from 1982–1985. Densities of small fish and zooplankton from surface waters were higher in slicks than in the rippled water adjacent to them. Presettlement fish, of species found as adults nearshore, were abundant in ichthyoplankton samples and visual counts from slicks. These fish ranged from fish with primordial fins to those with adult fin-ray counts. Some small reef fish aggregated around drift algae. Drift algae were also abundant in slicks. Slicks moved at 0.5 to 1.25 km h-1 in the direction of shore. Hence, a consequence of aggregation in slicks is that presettlement fish may be transported onshore. When slicks were absent, drift algae were found in scattered patches at different distances from shore. In the presence of slicks algae were aligned in them. Internal waves, therefore, may have the ability to turn scattered distributions into regular patterns. Because the surface slicks that internal waves produce are common coastal features, we should modify our perspective of how small fish and zooplankton are distributed in local water masses. Furthermore, the occurrence of internal waves should influence the way in which surface waters are sampled. We suggest that fish settlement patterns need to be investigated concurrently with measurements of physical mechanisms which may promote aggregation, and onshore movements of small fish (e.g. internal waves). These waves may contribute to the variability in settlement rates of small fish. 相似文献
5.
The distribution and behaviour of cormorants in estuarine environments was examined on the central coast of New South Wales,
Australia, with respect to habitat associations at different spatial scales. No consistent variation in abundance was found
for four species of cormorants (great Phalacrocorax carbo, pied P. varius, little black P. sulcirostris, and little pied P. melanoleucos) with state of tide (high and low) and time of day (early, middle, and late) at five estuarine locations. Differences in
abundance were found among locations that were not confounded by short-term temporal variation (i.e. time of day and tide).
Differences in abundance were detected among habitats (e.g. bays, creeks, and headlands) separated by hundreds of metres to
kilometres in different estuaries. Cormorants of all species were rare on the open coast and near the entrance of estuaries.
Abundances of cormorants varied greatly within and among creeks, bays, and river channels. Presence of seagrass beds explained
much of this variation and most of the cormorants swimming and feeding were found near seagrass. Mapping of seagrass beds
and the positions of cormorants at scales of metres to hundreds of metres showed a close relationship between the presence
of swimming and roosting beds and the presence of seagrass beds for P. melanoleucos and for P. carbo. We argue that cormorants make decisions to visit particular estuarine habitats, especially those with seagrass, where many
types of prey (e.g. fish and crustaceans) are probably most abundant. These choices must be interpreted in the context of
decisions that cormorants make on scales of hundreds to thousands of kilometres during periodic excursions to the interior
of Australia. Further, environmental threats to seagrass beds could impinge on these mobile visitors to the same extent as
on more permanent residents.
Received: 14 February 2000 / Accepted: 17 July 2000 相似文献
6.
The reproductive biology of the jellyfish Catostylus mosaicus (Quoy and Gaimard 1824) (Scyphozoa: Rhizostomeae) was investigated in New South Wales, Australia. Medusae were gonochoristic.
There was a 1:1 ratio of male and female medusae and there was no evidence of sexual dimorphism. Oocytes arose from the gastrodermis
and maintained contact with the gastrodermis, via trophocytes, throughout gametogenesis. Spermatogenesis occurred within follicles
that arose from invagination of the gastrodermis. Detailed sampling of gonads over a period of 3.25 yr in Botany Bay, and
over 2.5 yr in Lake Illawarra, indicated that gametogenesis occurred almost continuously during the year. Oocytes were smaller,
or were absent from the ovaries during 3 of the 4 winters sampled at Botany Bay and during all 3 winter periods sampled at
Lake Illawarra. Comparisons were made with other locations, although these were sampled less frequently. When medusae were
present at a location, similar trends were observed. The size at which medusae matured varied, but during non-winter periods
and at two locations, all medusae exceeding 130 mm diam were considered mature.
Received: 6 January 2000 / Accepted: 3 July 2000 相似文献
7.
M. J. Kingsford 《Marine Biology》2001,138(4):853-867
Most presettlement reef fish settled at night at One Tree Island, Great Barrier Reef. Fish were sampled day and night using
channel nets located on the reef crest, and a plankton-mesh purse-seine net in the lagoon (1992–1994). Catches of fish at
night were generally tens to hundreds of times greater than those taken during the day. Preflexion fish, as well as postflexion
and pelagic juveniles, were taken in greater numbers at night. Preflexion forms were a combination of those that had hatched
from demersal eggs and later stages that had been transported over the reef crest. Highest numbers of postflexion and pelagic
juvenile forms of Apogonidae, Blenniidae, Gobiesocidae, Gobiidae, Labridae, Lutjanidae, Mugiloididae, Mullidae, Pomacentridae,
Scaridae, Serranidae and Tripterygiidae were found at night. Observations, while SCUBA diving, and purse-seine samples in
the lagoon indicated that the only resident larvae were of the genera Spratelloides and Hypoatherina; most of the fishes caught in nets, therefore, were immigrants. Patch reefs, sampled for new settlers early in the morning
and late in the day, indicated that the majority of apogonids (Apogon doederleini, >95%) settled at night. Although greater numbers of pomacentrids were found in morning counts (e.g. Pomacentrus wardi), if data were converted to an hourly rate, many pomacentrids showed a similar hourly rate of settlement day and night. Depth-stratified
sampling in waters near One Tree Island (to 20 m) indicated that some taxa rise to the surface at night. This behaviour, perhaps
combined with avoidance of diurnal predators may explain on-reef movement of potential settlers soon after dark. Studies on
settlement cues, therefore, need to focus on night-related phenomena.
Received: 3 March 2000 / Accepted: 20 June 2000 相似文献
8.
9.
10.
The relationship between densities of Achoerodus viridis (Pisces: Labridae) and reef habitats at various localities within New South Wales (NSW), Australia was examined. Types of
habitats were quantified at inner, mid and outer estuarine locations in each of two estuaries (Botany Bay and Port Jackson)
to determine whether purported patterns of movement from estuaries could be related to differences in habitat. Although the
same types of habitat were generally found at all locations, differences in the proportion of habitat types were found between
shallow and deep reefs and among inner, mid and outer estuarine locations for both estuaries. Shallow habitats were usually
dominated by Ecklonia radiata, turf and/or fringe habitat in Botany Bay, whereas deep sites were generally dominated by urchin-grazed barrens habitat and,
sometimes, sponge- and ascidian-dominated deep reef. Shallow sites in Port Jackson were dominated by a mixture of habitats,
as were deep reefs at mid-estuarine locations. Other deep reefs in Port Jackson were dominated by E. radiata (inner estuarine) or barrens (outer estuarine) habitat. Thus, patterns of habitat cover were not consistent between estuaries
and numbers of fish could not be related to proportional representation of habitat on reefs along estuarine gradients. Univariate
and multivariate analyses showed that there was little evidence that any size class of fish was correlated with the proportional
representation of a particular habitat or group of habitats. Counts of fish that focused on barrens and E. radiata forest habitats over a period of 10 yr showed that similar numbers and all sizes of fish were found in the two types of habitat.
Greater numbers of small fish were, however, found in the E. radiata forest habitat than in the barrens habitat. Estimates of abundance along the coast of NSW (100s to 1000 km) in a range of
habitats (e.g. ascidian-dominated reef, kelp forest, urchin-grazed barrens) showed that there was no indication that a particular
habitat consistently had greater numbers of A. viridis than other habitats. Therefore, A. viridis of a range of sizes appears to be flexible in its use of habitats on reefs.
Received: 24 December 1997 / Accepted: 23 June 1998 相似文献