Ecotones, ecoclines and eco-perturbations: the aquatic flora and fauna of S'Albufera Natural Park, Mallorca: a contribution and review

The S’Albufera Natural Park in Majorca protected nationally as a Natural Park; as an EU Special Protection Area for Birds (SPA); as a Wetland of International Importance under the Ramsar Convention and is the most extensive area of marshlands in the Balearics at the brackish interface between seawater and the freshwater inflow from the hinterland of Majorca. It is suggested that the whole marsh aquatic system is a saline freshwater gradient or ecocline containing a series of ecotones or sharp interfaces between differing aquatic and terrestrial habitats and these change with time resulting in a dynamic niches for plants and animals leading to the rich biodiversity of the site. The author reviews some of the existing literature relating to the site, particularly related to the aquatic flora of the brackish water ecocline to which new data are added and the significance of these changing habitat interfaces i.e. ecotones to the present ecology and conservation of the Park

Ecotones, ecoclines and eco-perturbations: the aquatic flora and fauna of S'Albufera Natural Park, Mallorca: a contribution and review

The S’Albufera Natural Park in Majorca protected nationally as a Natural Park; as an EU Special Protection Area for Birds (SPA); as a Wetland of International Importance under the Ramsar Convention and is the most extensive area of marshlands in the Balearics at the brackish interface between seawater and the freshwater inflow from the hinterland of Majorca. It is suggested that the whole marsh aquatic system is a saline freshwater gradient or ecocline containing a series of ecotones or sharp interfaces between differing aquatic and terrestrial habitats and these change with time resulting in a dynamic niches for plants and animals leading to the rich biodiversity of the site. The author reviews some of the existing literature relating to the site, particularly related to the aquatic flora of the brackish water ecocline to which new data are added and the significance of these changing habitat interfaces i.e. ecotones to the present ecology and conservation of the Park

Craig Goch Report No. 15 Macroinvertebrates of the River Wye

Except for a single summer survey in 1970 (Radcliffe 1977) no significant investigations of the invertebrate fauna of the R. Wye have been undertaken. The objectives of the present study are to determine a sampling strategy which will provide a description of the distribution and relative abundance of aquatic macroinvertebrates in the R. Wye and those tributaries associated with proposals to regulate flow in the river system. In addition to fulfilling basic biological objectives, such as the description of community diversity and the incidence of taxa of particular significance, because of their rarity or usefulness as ‘indicator’ species, such a strategy must take account of operational preferences. Such preferences will be governed by river flow, the availability of support staff and the temporal stability of macroinvertebrate communities. This report considers the efficiency and efficacy of the timing of general surveys in 1975 and 1976 and the usefulness of certain survey sites

Craig Coch Field Surveys Group meeting, Malvern February 1976: UWIST Paper 7. River Wye vegetation survey

The problem as stated in the contract for this survey is that “the River Wye is regarded as a Grade 1 site in the Nature Conservation Review. The enlargement of an existing reservoir at Craig Goch in Powys intended eventually to regulate the river flow within the Wye and Severn could have an undesirable and adverse effect upon the ecology and Nature Conservation interest of the River Wye.” The object of this survey, again as stated in the Nature Conservancy Council contract, is “to determine the distribution of aquatic and marginal plants within the River, Wye, which is defined loosely as the river plus its retaining banks. To study aspects of the ecology of riparian habitats by relating distribution to recorded variables, and suggest possible means of management.” It is proposed that the vegetation survey is to take 60% of the available time and the experimental side 40%. Mr. D.G. Merry has been appointed as a research assistant for three years to work on the project under the supervision of Dr. F.M. Slater

Craig Coch Field Surveys Group meeting, Malvern 3-4 February 1976: UWIST Paper 3. Comparison of two methods of collecting macro-invertebrates from the R. Wye

The adequacy of different methods of sampling invertebrates for the collection of qualitative and quantitative information for surveillance purposes has been the centre of discussion at Craig Goch Surveys Group meetings (Abel, 1975). This paper compares two methods of collecting macro-invertebrates from the R. Wye

Craig Coch Field Surveys Group meeting, Malvern February 1976: UWIST Paper 4. Invertebrates: River Wye

Except for a single summer survey by Morgan (1970) no significant investigations of the invertebrate fauna of the R. Wye have been undertaken as far as we are aware. The current programme was designed to describe the distribution and relative abundance of aquatic invertebrates, in the R. Wye and those tributaries relevant to the proposals to regulate discharge in the river system. In addition, a more intensive localised study has been established to describe the population dynamics of selected invertebrate communities more precisely and to establish the feasibility of assessing the effect of secondary production of regulating discharges. Complementary studies on the drift of invertebrates have been undertaken. These data will be needed as a basis for evaluating the effects of the proposed Craig Goch scheme on the invertebrate fauna in the Wye catchment

Craig Coch Field Surveys Group meeting, Malvern February 1976: UWIST Paper 5. Invertebrate studies: Ystwyth & Rheidol

The Rivers Ystwyth and Rheidol have a history of metal pollution (Carpenter 1924, 1925: Newton 1944): many reaches still receive substantial volumes of water contaminated with heavy metals, principally zinc and lead, although there has been considerable improvement in water quality and biological status in recent years, particularly in the R. Rheidol (Jones & Howells 1969). As a consequence of proposals to divert uncontaminated water from the headstreams of both rivers in order to provide a refill source for the enlarged Craig Goch Reservoir, a surveillance programme was instituted to provide base-line data for water quality, fisheries and invertebrates. U.W.I.S.T., under contract to W.N.W.D.A., has implemented a programme which will provide information on the variety, distribution and relative abundance of aquatic invertebrates: the study of other aspects has been undertaken by South West Wales River Division (1976)

Craig Coch Field Surveys Group meeting, Malvern February 1976: UWIST Paper 6. Submerged macrophytes of the R. Wye

Substantial growths of aquatic macrophytes are known to occur in the lower reaches of the R. Wye during the summer months and in 1975 the distribution of major plant species was assessed and the biomass of representative plant stands estimated in one 30 km stretch. This very modest programme has now been complemented by a more comprehensive study of macrophytes of the R. Wye by UWIST, under contract to Nature Conservancy Council (UWIST 1976g)

Craig Coch Field Surveys Group meeting, Malvern February 1976: UWIST Paper 2. Fisheries studies - R. Wye

Although the Wye is well known for its salmon fisheries, no data, other than very basic fisheries statistics (Wye River Division Annual Reports) are available to assess the status of these fisheries. The current programme, primarily restricted to the upper reaches of the river where the effects of regulation are likely to be greatest, is intended to describe the distribution of salmonid and coarse fish and to assess the stock of salmonid species. In a large river like the Wye where conventional sampling techniques are generally inadequate (E.I.F.A.C. 1974) only certain species and life-stages are likely to be sampled adequately. In order to supplement data collected from the main river a number of representative tributaries, above and below the proposed point of regulation of the river have been studied, primarily to obtain base-line data so that any major change in the distribution of salmon can be detected. In order to establish some relationship between spawning adult salmon and recruitment, a programme of adult trapping on a nursery tributary was undertaken during November and December 1975. In conjunction with W.N.W.D.A. (Brecon) and the Wye River Division, a programme has been designed to assess the catchability of adult salmon in the River Wye