Habitat Creation Opportunities for Landward Coastal Re-alignment: Essex Case Studies

Relative sea-level fluctuations during the Holocene period have combined with medieval to present saline floodplain embanking to reduce the inter-tidal saltmarsh area in Essex from 40 000 ha to 4400 ha. The present loss by erosion is estimated at 2%/annum for the country, and the reduction in these areas is not only detrimental to related habitats but has caused an increasing requirement for flood-defence financial investment.
Recent initiatives by the Ministry of Agriculture, Fisheries and Food, the Environment Agency and English Nature have created mechanisms and opportunities to develop sustainable flood-control structures where coastal re-alignment has been the preferred option.
The Orplands frontage covers 2 km of sea wall which have been deliberately breached to allow 40 ha of rare saltmarsh to re-establish. At Abbotts Hall, an arable field of 20 ha has been converted to its former saltmarsh by creek re-establishment and tidal inundation by reversal of existing sluices. These two schemes have (a) regenerated habitats for halophytic and semi-halophytic plants, marine and brackish invertebrates, and (b) provided roost, feed and breeding areas for birds and nursery areas for marine fish fry. Apart from flood control and habitat creation, particular features were incorporated to provide niche locations for targeted types of wildlife.     

Methylmercury Concentrations Found in Wild and Farm-raised Paddlefish

ABSTRACT: Paddlefish ( Polyodon spathula ) were collected from 4 sites in Kentucky: the Ohio River, Lake Cumberland, and 2 aquaculture sources (private reservoir and catfish ponds). They were tested for methylmer-cury concentrations in their flesh. Paddlefish from all sources had methylmercury levels below the 1 part per million Food and Drug Administration-mandated action limit for seafood. However, using the U.S. Environmental Protection Agency reference dose for methylmercury, only paddlefish from the Ohio River exceeded the reference dose for unrestricted consumption. Some Ohio River and Lake Cumberland paddlefish had higher-than-average methylmercury concentrations, whereas aquacultured paddlefish had low concentrations of methylm-ercury. There was a direct proportionality between fish age and methylmercury concentration; older paddlefish tended to have higher amounts of methylmercury in their meat.     

CHARACTERIZATION OF THE PROTEASES INVOLVED IN HYDROLYZING PADDLEFISH (POLYODON SPATHULA) MYOSIN

An extract from paddlefish surimi possessed activities of B, L, and H‐like cathepsins. The optimal pH was around 5.0 for cathepsins B and L, and was between 6.0–6.5 for the H‐like cathepsin. The enzyme activities were not impaired by heating at 40Cfor 20 min. However, the protease extract lost about 20% of its cathepsin B, 50% B+L, and 90% H‐like cathepsin activities after heating at 50C for 20 min. The activity of H‐like cathepsin was not inhibited by E‐64, suggesting that it did not belong to ike known cysteme protease group. The protease extract was capable ofhydrolyzing myosin heavy chain, producing a major fragments) around 140 kDa. Degradation of myosin by the protease extract was substantially reduced by protease inhibitors including E‐64, a protease inhibitor mixture, and bovine plasma powder.