The Kent estuary 1992 surveys. Summary of results

This is the Kent estuary 1992 surveys: Summary of results produced by the National Rivers Authority in 1993. The report summarises routine and baseline water quality surveys carried out on the Kent estuary during 1992. Baseline surveys are designed to respond to regional, national, and European requirements. During 1992 baseline surveys were carried out in June and December. Unfortunately, in June, samples could only be taken from stations 3, 7 and 8. For ease of interpretation the results have been presented in graph form, including the maximum and minimum parameter concentration and the appropriate Environmental Quality Standards (EQS). The parameters measured in this survey were physical parameters (temperature, BOD, dissolved oxygen, Ph, salinity, conductivity); nutrients (ammonia, phosphate, and nitrate); metals (Mercury, Nickel, Arsenic, Cadmium, Chromium, Cooper, Boron, and Zinc) and organic compounds.

Muskrats on tidal marshes of Dorchester County

This bulletin reports, in a non-technical manner, investigations on the Virginia muskrat, prevalent in Maryland, from July, 1949 to June, 1951.

Prioritizing county-level well-being: Moving toward assessment of Gulf Coast counties impacted by the Deepwater Horizon Industrial Disaster

To develop a portfolio of indicators and measures that could best measure changes in the social, economic, environmental and health dimensions of well-being in coastal counties we convened a group of experts March 8-9, 2011 in Charleston, SC, U.S.A. The region of interest was of the northern Gulf of Mexico, specifically, those coastal counties most impacted during the explosion and subsequent oil spill from the Macondo Prospect wellhead during the summer of 2010. Over the course of the two-day workshop participants moved through presentations and facilitated sessions to identify and prioritize potential indicators and measures deemed most valuable for capturing changes in well-being related to changes in or disruption of ecosystem services. The experts reached consensus on a list of indicators that are now being operationalized by NOAA researchers. The ultimate goal of this research project is to determine whether a meaningful set of social and economic indicators can be developed to document changes in well-being that occur as a result of changes in ecosystem services. The outcomes and outputs from the workshop that is the subject of this report helped us to identify high-quality indicators useful for measuring well-being.

Trends in counts of manatees Trichechus manatus latirostris from 1987 to 2006 in waters of Sarasota County, Florida, USA

To demonstrate the utility of distributional surveys for assessing relative abundance and trends in counts for a discrete area of coastline, aerial survey data from Sarasota County, Florida, USA, were analyzed for the years 1987 to 2006. The study area was divided into 3 regions: the Sarasota Bay Region (SBR; N = 353 surveys), Lemon Bay (N = 368), and the Myakka River (N = 209). Manatee counts varied significantly across seasons (p < 0.0001) for all 3 regions. Manatees within Sarasota County utilized open bays primarily in the warmer months. Such usage may have been influenced by resource availability. Conversely, usage of the Myakka River peaked in winter months when manatees seek warm-water refugia such as Warm Mineral Spring. Marginal means for yearly counts within Lemon Bay and the SBR increased significantly, beginning midway through the survey period (1996) until the early 2000s. In contrast, mean yearly counts within the Myakka River decreased over this time period. After record lows in 2003 for Lemon Bay and the Myakka River, and a considerable decline in 2004 for the SBR, mean yearly counts for all 3 regions showed an increasing trend over the remaining 2 yr of the study. Greater protection of manatee habitat and availability of forage coincided with the increase in numbers of manatees using Sarasota County waters during the 1990s, and the subsequent decline in numbers may be indicative of the increase in mortality in recent years due to watercraft collisions and severe red tide events.

Seasonal distribution, abundance, and growth of young-of-the-year Atlantic croaker (Micropogonias undulatus) in Delaware Bay and adjacent marshes

We examined the spatial and temporal distribution, abundance, and growth of young-of-the-year (YOY) Atlantic croaker (Micropogonias undulatus) in Delaware Bay, one of the northernmost estuaries in which they consistently occur along the east coast of the United States. Sampling in Delaware Bay and in tidal creeks in salt marshes adjacent to the bay with otter trawls, plankton nets and weirs, between April and November 1996–99, collected approximately 85,000 YOY. Ingress of each year class into the bay and tidal creeks consistently occurred in the fall, and the first few YOY appeared in August. Larvae as small as 2–3 mm TL were collected in September and October 1996. Epibenthic individuals <25 mm TL were present each fall and again during spring of each year, but not in 1996 when low water temperatures in January and February apparently caused widespread mortality, resulting in their absence the following spring and summer. In 1998 and 1999, a second size class of smaller YOY entered the bay and tidal creeks in June. When YOY survived the winter, there was no evidence of growth until after April. Then the YOY grew rapidly through the summer in all habitats (0.8–1.4 mm/d from May through August). In the bay, they were most abundant from June to August over mud sediments in oligohaline waters. They were present in both subtidal and intertidal creeks in the marshes where they were most abundant from April to June in the mesohaline portion of the lower bay. The larger YOY began egressing out of the marshes in late summer, and the entire year class left the tidal creeks at lengths of 100–200 mm TL by October or November when the next year class was ingressing. These patterns of seasonal distribution and abundance in Delaware Bay and the adjacent marshes are similar to those observed in more southern estuaries along the east coast; however, growth is faster—in keeping with that in other northern estuaries.

Assessment of sampling methods to estimate horseshoe crab (Limulus polyphemus L.) egg density in Delaware Bay

Each spring horseshoe crabs (Limulus polyphemus L.) emerge from Delaware Bay to spawn and deposit their eggs on the foreshore of sandy beaches (Shuster and Botton, 1985; Smith et al., 2002a). From mid-May to early June, migratory shorebirds stopover in Delaware Bay and forage heavily on horseshoe crab eggs that have been transported up onto the beach (Botton et al., 1994; Burger et al., 1997; Tsipoura and Burger, 1999). Thus, estimating the quantity of horseshoe crab eggs in Delaware Bay beaches can be useful for monitoring spawning activity and assessing the amount of forage available to migratory shorebirds.

Abundance of horseshoe crabs (Limulus polyphemus) in the Delaware Bay area

In recent years, increasing commercial landings of horseshoe crabs (Limulus polyphemus) along the Atlantic coast of the United States have raised concerns that the present resource is in decline and insufficient to support the needs of its user groups. These concerns have led the Atlantic States Marine Fisheries Commission (ASMFC) to implement a fishery management plan to regulate the harvest (ASMFC1). In order to properly manage any species, specific management goals and objectives must be established, and these goals depend on the resource users involved (Quinn and Deriso, 1999). Horseshoe crabs present a distinct resource management challenge because they are important to a diverse set of users (Berkson and Shuster, 1999).

Water quality studies of the Delaware River with reference to shad migration

For some time pollution of the waters of the Delaware River by municipal and industrial wastes has been suspected of playing a major role in the decline of the shad fishery. Accordingly, studies were planned to ascertain whether any conditions of water quality caused by stream pollution and harmful or lethal to shad were existant in the waters of the Delaware River during the migration periods of the shad.

Bird and mammal conservation in Gaoligongshan Region and Jingdong County, Yunnan, China: patterns of species richness and nature reserves

Elevational and latitudinal patterns of species richness for birds and mammals were compared with human population density in relation to nature reserve designation in two areas of Yunnan Province, China. Results suggest that species richness is not the same for the two areas. In Gaoligongshan Region, species richness is inversely correlated with elevation and altitude, while reserve designation is positively correlated with elevation and latitude. In Jingdong County, reserve designations are positively correlated with elevation, but species richness shows no clear trends. In general, the present situation is strongly influenced by human activities. It appears that reserve designation is mismatched with species richness in Gaoligongshan Region, while there is a better fit between the two in Jingdong County. In both areas, however, it appeared that reserves were located primarily in order to reduce conflict with humans rather than to maximize conservation of biodiversity, probably because humans were responsible for forest-especially primary forest-destruction and degradation in the low-lying areas.