Dull adnabod

Dynodydd

NRW_DS101997

Teitl Amgen

• 2005 CCW HABMAP sublittoral survey MRCCW16900000002
• 2005 CCW / IECS Pembrokeshire Marine SAC Milford Haven rocky reef monitoring MRCCW30200000018
• Monitro Rhynglanwol: Riffiau Creigiog yn Aberdaugleddau, ACA Sir Benfro Forol

Laith Metadata

English

Datganiad

This dataset contains the results of a baseline survey of fixed quadrats across six rocky shore sites within the Milford Haven waterway in July 2005. The sites were chosen to represent an environmental gradient along the Haven in terms of salinity and wave exposure to mirror transects established by OPRU in 1995. However site selection was limited by the need to select sites that had suitable bedrock for permanent marking, reliable and reasonable access and suitable habitat throughout the shore. At each site samples were taken from three different shore heights- upper shore, middle shore and lower shore. Within each shore zone four 1m x 1m quadrats were permanently marked (placed in homogenous areas of inclined rock where possible, avoiding rock pools and large fissures). Photographs were taken of all quadrats and a habitat map produced to facilitate relocation. Within each 1m2 quadrat presence/absence data were recorded for all species using a 25 cell grid. This gave a frequency score of between 0 and 25 for each species. Organisms were identified to species level where possible with specimens being returned to the laboratory for verification where necessary. Species within the following taxa were aggregated for cell counts: barnacles, limpets, flat winkles, rough winkles, amphipods, Verrucaria spp (except Verrucaria mucosa). Further data were captured at the six sites via limpet counts, limpet population profile, barnacle species abundance, barnacle abundance, collection of small molluscs and crustacea and Ascophyllum nodosum population structure. The current survey provides baseline data for future comparisons. Data from previous surveys exist for five of the six sites, however previous monitoring was generally in the form of transect surveys using SACFOR abundance assessment (which has less resolution for detection of population change). As a consequence, results from these studies are not directly comparable to the data collected from this set of surveys.

Dyddiad cyfeirnod y set ddata (Cyhoeddiad)

2008-12-31

Rhychwant

Rhychwant

Hyd

SIR BENFRO - PEMBROKESHIRE

Hyd

Wales (WLS)

N

W

E

S

 

Dosbarthiad

Ansawdd

Allweddeiriau

System Cyfeirio Gofodol

Cynnwys

Cyfyngiadau