Temporal and spatial aspects of bottlenose dolphin occurrence in coastal and estuarine waters near Charleston, South Carolina

The spatial and temporal occurrence of Atlantic bottlenose dolphins (Tursiops truncatus) in the coastal and estuarine waters near Charleston, SC were evaluated. Sighting and photographic data from photo-identification (ID), remote biopsy, capture-release and radio-tracking studies, conducted from 1994 through 2003, were analyzed in order to further delineate residence patterns of Charleston area bottlenose dolphins. Data from 250 photo-ID, 106 remote biopsy, 15 capture-release and 83 radio-tracking surveys were collected in the Stono River Estuary (n = 247), Charleston Harbor (n = 86), North Edisto River (n = 54), Intracoastal Waterway (n = 26) and the coastal waters north and south of Charleston Harbor (n = 41). Coverage for all survey types was spatially and temporally variable, and in the case of biopsy, capture-release and radio-tracking surveys, data analyzed in this report were collected incidental to other research. Eight-hundred and thirty-nine individuals were photographically identified during the study period. One-hundred and fifteen (13.7%) of the 839 photographically identified individuals were sighted between 11-40 times, evidence of consistent occurrence in the Charleston area (i.e., site fidelity). Adjusted sighting proportions (ASP), which reflect an individual’s sighting frequency in a subarea relative to other subareas after adjusting for survey effort, were analyzed in order to evaluate dolphin spatial occurrence. Forty-three percent (n = 139) of dolphins that qualified for ASP analyses exhibited a strong subarea affiliation while the remaining 57% (n = 187) showed no strong subarea preference. Group size data were derived from field estimates of 2,342 dolphin groups encountered in the five Charleston subareas. Group size appeared positively correlated with degree of “openness” of the body of water where dolphins were encountered; and for sightings along the coast, group size was larger during summer months. This study provides valuable information on the complex nature of bottlenose dolphin spatial and temporal occurrence near Charleston, SC. In addition, it helps us to better understand the stock structure of dolphins along the Atlantic seaboard.

硼对植物生殖器官建成的作用

实验以黄瓜植物为材料，研究了硼在个体水平上和器官水平上对植物生殖器官建成的作用，并用放射性同位素示踪法研究了硼对植物生殖器官的作用同植物体内糖运输的关系。结果表明，在个体水平上，缺硼使植物体上雄花和雌花数目都减少，但缺硼对雌花形成和雄花形成的影响并不相同，缺硼使植物体上形成较多的雄花，较少的雌花。在器官水平上，硼的作用同它的浓度有关，在某一浓度范围内，缺硼不利于黄瓜花蕾发育成雌花-也不利于雄花花药的发育;硼浓度的升高有利于花蕾发育成雌花，也有利于发育成雄花的花蕾花药的发育。较高浓度的硼则明显使黄瓜花蕾不易发育成雌花，但有利于发育成雄花的花蕾花药的发育。在个体水平上，缺硼对生殖器官建成的作用同花蕾组织中可溶性糖的缺乏有关，这可能是由于缺硼抑制了茎等输导组织的糖吸收活动而使叶片光合作用所合成的糖不易运到花蕾中的原因。

Practicing coastal seascape ecology

Landscape ecology concepts developed from terrestrial systems have recently emerged as theoretical and analytical frameworks that are equally useful for evaluating the ecological consequences of spatial patterns and structural changes in the submerged landscapes of coastal ecosystems. The benefits of applying a spatially-explicit perspective to resource management and restoration planning in the coastal zone are rapidly becoming apparent. This Theme Section on the application of landscape ecology to the estuarine and coastal environment emerged from a special symposium at the Coastal and Estuarine Research Federation (CERF) 20th Biennial Conference (Estuaries and Coasts in a Changing World) held in Portland, Oregon, USA, in November 2009. The 7 contributions in this Theme Section collectively provide substantial insights into the current status and application of the landscape approach in shallow marine environments, and identify significant knowledge gaps, as well as potential directions for the future advancement of ‘seascape ecology’.

Feeding on protists and particulates by the leptocephali of the worm eels Myrophis spp. (Teleostei: Anguilliformes: Ophichthidae), and the potential energy contribution of large aloricate protozoa

The food sources of the leptocephali of the teleostean superorder Elopomorpha have been controversial, yet observations on the leptocephali of the worm eels, Myrophis spp. (family Ophichthidae) collected in the northern Gulf of Mexico indicate active, not passive, feeding. Leptocephali had protists in their alimentary canals. Estimates of the physiological energetics of worm eels indicate that large aloricate protozoa including ciliates could provide substantial energy to these leptocephali toward the end of the premetamorphic and metamorphic stages, given the low energy requirements of metamorphosing leptocephali. Global ocean warming will likely force a shift in oceanic food webs; a shift away from large protozoa toward smaller protists is possible. Such a disruption of the oceanic food webs could further compromise the survival of leptocephali.