Search USGSSearch

Geology topics

Steven J. Parker

Publications and source records attributed to Steven J. Parker.

2 recordsLinked to original sources

A systematic approach towards the identification and protection of vulnerable marine ecosystems

The United Nations General Assembly in 2006 and 2009 adopted resolutions that call for the identification and protection of vulnerable marine ecosystems (VMEs) from significant adverse impacts of bottom fishing. While general criteria have been produced, there are no guidelines or protocols that elaborate on the process from initial identification through to the protection of VMEs. Here, based upon an expert review of existing practices, a 10-step framework is proposed: (1) Comparatively assess potential VME indicator taxa and habitats in a region; (2) determine VME thresholds; (3) consider areas already known for their ecological importance; (4) compile information on the distributions of likely VME taxa and habitats, as well as related environmental data; (5) develop predictive distribution models for VME indicator taxa and habitats; (6) compile known or likely fishing impacts; (7) produce a predicted VME naturalness distribution (areas of low cumulative impacts); (8) identify areas of higher value to user groups; (9) conduct management strategy evaluations to produce trade-off scenarios; (10) review and re-iterate, until spatial management scenarios are developed that fulfil international obligations and regional conservation and management objectives. To date, regional progress has been piecemeal and incremental. The proposed 10-step framework combines these various experiences into a systematic approach.

Marine Science

Geological characterization of selected offshore sand resources on the OCS, offshore Alabama, for beach nourishment

Most Alabama Gulf and estuarine shoreline is undergoing long-term erosion; threatened shorelines will need programs of replenishment and maintenance if they are to be even temporarily stabilized. Highest priority beach replenishment areas include eastern Dauphin Island; west of Perdido Pass; and west of the inlet at Little Lagoon. There are no appropriate local onshore sand sources available for any such large scale program. Sediments in the Federal waters of the EEZ were evaluated for possible sources of sand for beach nourishment. Six lithofacies were delineated based on sediment characterization, spatial framework, and environment of deposition; of these, two (Clean Sands and Graded Shelly Sands) were deemed to have highest potential as beach nourishment sources. Five offshore target areas were delineated as potential sand sources. Criteria included sand aesthetics, estimated sand volume, and sand distributions. Preliminary environmental analyses included impacts of offshore sand dredging on shelf circulation; on economic activities; and on local benthic biota. Dredging may not significantly alter background wave regimes; however, data are insufficient to model effects of major storms on a modified shelf morphology. Dredging would avoid areas of current economic activity. There would like be little long-term impact on benthic biota in the target areas. Additional work will be required to confirm or refute these preliminary findings.

Conference Paper