✦ LIBER ✦

Effects of seasonal variation in salinity on a population of Enochrus bicolor Fabricius 1792 (Coleoptera: Hydrophilidae) and implications for other beetles of conservation interest

✍ Scribed by M.T. Greenwood; P.J. Wood

Publisher: John Wiley and Sons
Year: 2003
Tongue: English
Weight: 303 KB
Volume: 13
Category: Article
ISSN: 1052-7613
DOI: 10.1002/aqc.517

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✦ Synopsis

Abstract

A population of Enochrus bicolor (Fabricius) was monitored over a 4‐year period (March 1997–March 2001) from a coastal brackish pool in S.E. Essex. This water beetle, together with Ochthebius marinus (Payk__.), O. viridis__ Peyrhiff, O. punctatus Steph., Hygrotus parallelogrammus (Ahrens), Berosus affinis Brulle, Agabus conspersus, (Marsham), Rhantus frontalis (Marsham), R. suturalis (MacLeay), Paracymus aeneus (Germar), and Haliplus apicalis Thompson, are all taxa of conservation interest.

Enochrus bicolor was present in most months, with greatest adult abundances being recorded in August and September each year.

During the study period salinity values ranged from 4.7 ppt (parts per thousand) to 62.6 ppt.

Correlation analysis and the development of regression models indicated that the highest abundances of E. bicolor coincided with maximum water temperature in the late summer–early autumn. However, when the natural seasonal signal was removed by standardizing the series, a relatively weak association with the relative abundance of E. bicolor and conductivity was observed.

The conservation of E. bicolor and other organisms associated with brackish water habitats subject to irregular marine inundation is considered.