A.C. Jensen

Lobster (Homarus Gammarus) Movement On an Artificial Reef: the Potential Use of Artificial Reefs for Stock Enhancement

In 1989 an experimental artificial reef, constructed with blocks made from stabilized coal-fired power station waste materials, was deployed in Poole Bay on the English south coast. A site was chosen on flat sandy seabed at a depth approximately 10 m below chart datum. Within a few weeks, research divers had observed lobsters on the reef, even though the reef blocks had been deposited on flat sand some distance (3 km) from the nearest natural reefs. Conventional tags were used in studies to investigate lobster movement around the reef structure between 1989 and 1992: 48% of the 114 individuals tagged have been recaptured at least once on the reef. Although a number of lobsters appear to have moved away from the reef altogether (16 of the reef-tagged lobsters have now been recaptured at a maximum of 15.7 km away from the artificial reef), one individual has now been observed on the reef for over 800 days. Lobsters colonized the new man-made structures quickly and many individuals have exhibited considerable long-term site loyalty. Artificial reefs may provide a method for long term lobster stock enhancement at specific sites, assuming habitat to be a major limiting factor on population size and structure.

A Review of Waste Tyre Utilisation in the Marine Environment

Abstract Waste tyres pose a major disposal problem on land creating a fire hazard and, in warmer climates, providing breeding pools for mosquitoes. the void space in tyres makes them unsuitable for land burial. Schemes to use shredded tyres for road bases and asphalt filler are being pursued in the USA. Tyre combustion for electricity production is being investigated in the UK. The widespread availability and durability of tyres has led to their use in the marine environment for breakwaters/coastal defence structures and as artificial reefs for promoting fisheries. Tyres have a low density and have been used in floating breakwaters. Schemes have been proposed to protect and strengthen shorelines with tyre structures. The void space in tyres facilitates the construction of artificial reefs to attract fish. the most intensive use is in the south west Pacific and Australia. Tyre surfaces are colonised by algae and a wide range of faunal species, including corals and shellfish. the wide acceptance of tyres as...

Overview on artificial reefs in Europe

Artificial reefs in Europe have been developed over the last 40 yrs. Most of these reefs have been placed in the Mediterranean Sea, but there is an increasing interest on the part of northern European countries. Fish stock enhancement and fishery management are the main purposes of reef construction in the Mediterranean Sea and on the Atlantic coast of the Iberian Peninsula, while nature conservation/restoration, research, and recreation have been the main purposes served in the other European regions to date. Artificial reef deployment falls under some general regulations concerning the protection of the sea against pollution due to the dumping of unsuitable materials. Specific Regional Plans relating to the use of artificial reefs in the marine environment and Guidelines for reef construction have been derived from these general regulations. In spite of recent developments, national and/or regional programs for the deployment of artificial reefs and/or their inclusion in overall management plans for integrated management of coastal zones are in force only in the majority of Mediterranean countries, while only a few projects have, to date, been undertaken in the other European Regions. Moreover, there is a noteworthy lack of plans, in many countries, for the management of the reefs after their deployment.

Fishery Enhancement Reef Building Exercise

Abstract The constructive use of coal-fired power station waste products for building artificial reefs is being explored for the first time in the U.K. at present, the practice of sea dumping of raw pulverised fuel ash (PFA) from coal combustion is under review and the use of consolidated PFA blocks offers a possible alternative. the planned fitting of flue gas desulphurisation (FGD) plant in the U.K. will additionally produce large quantities of gypsum. to test the environmental compatability of such materials in marine structures, an experimental reef has been constructed off the central south coast of the U.K. Fifty tonnes of blocks made from different combinations of PFA, gypsum, FGD waste water sludge, cement and gravel using standard concrete as the control material, were deployed. the site selected is remote from prominent sea bed features in an area of flat sand with limited species variety.The preliminary studies leading to the licensing of this project included bioassay experiments with diatom c...

Digital electromagnetic telemetry system for studying behaviour of decapod crustaceans.

1 year and the receiving system batteries are replaced by divers at intervals of up to 4 weeks. In field tests, crab (Cancer pagurus L.) and lobster (Homarus gammarus (L.)) activity was monitored at an artificial reef for 14 months. Examples of the type of information acquired are presented to illustrate the capabilities of the system and potential applications are discussed. Limitations of digital electromagnetic telemetry stem mainly from the short range of detection, the need for cables on the seabed and the size and shape of the transmitting tag.

Stability of a coal waste artificial reef

Abstract The feasibility of using U.K. coal-fired power station waste materials for artificial reef production is being examined. in June, 1989, an experimental artificial reef was constructed in Poole Bay, off the central south coast of the U.K., using three different mixtures of pulverised fuel ash (PFA), flue gas desulphurisation (FGD) gypsum and slurry, stabilized with cement and formed into blocks. Fifty tonnes of 40 × 20 × 20 cm blocks were formed into eight conical reef units replicating three different PFA/gypsum mixtures and one concrete control. the reef structure is 10m below chart datum on a flat sandy sea-bed. Combustion of coal concentrates the heavy metal content in the resultant ash. the purpose of stabilization of the ash as blocks is twofold: to immobilize heavy metals (or other components) and to provide hard substratum for the attachment of organisms. to examine the effectiveness of this stabilization and hence the environmental compatibility of the block materials, heavy metal (Cd, Cr...

The Poole Bay artificial reef project

Artificial reef research is relatively new in the UK. The Poole Bay artificial reef was the second licensed reef in the UK, the first being a little-investigated quarry rock reef off the east coast of Scotland (Todd et al, 1992). The Poole Bay reef is unique in Northern Europe, being the first artificial reef made from cement- stabilized pulverized fuel ash (PEA) and flue gas desulphurization (FGD) gypsum derived from power stations. The reef was designed to assess the environmental acceptability of this novel material and was deployed in Poole Bay, off the central south coast of England, in June 1989 (Fig. 1).

13. The Manila Clam in Poole Harbour

Abstract The Manila Clam Tapes philippinarum was introduced to Poole Harbour in 1989 as a novel species for aquaculture. Contrary to expectations this species has become naturalized in the harbour, probably the northernmost location in Europe for this to occur. The chapter discusses possible reasons why this should have happened. The naturalized clam is now fished extensively in the western part of the harbour and preliminary data suggest that the pump-scoop method of fishing does not increase the degree of infaunal community disturbance (as measured by an ABC plot), but may have some effect on the sediment character.

The Potential Use of Artificial Reefs to Enhance Lobster Habitat

Artificial reefs provide habitat which is exploited in a variety of ways by the marine life associated with them. UK researchers interested in lobster (Homarus gammarus (L.)) stock enhancement, artificial reefs, and design criteria for artificial reefs, are collaborating to address the possibility of designing, building and stocking artificial reefs to enhance lobster populations. As lobster habitat requirements are determined so the assessment of natural habitat to hold lobsters is facilitated. The knowledge gained will allow fishery managers to evaluate the worth of possible restocking programmes to supplement or extend the range of local lobster populations.

Stabilized Coal Ash Artificial Reef Studies

Abstract In 1989, an experimental stabilized coal ash reef was deployed in Poole Bay off the southern coast of the UK. Three different mixtures of pulverised fuel ash, gypsum, flue gas desulphurisation sludge and cement were used along with concrete controls. the aim was to study the environmental compatibility of the reef materials through heavy metal analyses of the blocks to determine if any leaching or changes were occurring. at the same time, reef encrusting and associated biota have been analyzed together with material from concrete control and natural reefs to determine if there was any evidence for excess bioaccumulation. This paper presents the results from studies of sectioned reef blocks immersed for 3 and 4 years. No significant change in levels of heavy metals (Cd, Cr, Cu, Mn, Ni, Pb, Zn) has been detected. Surface loss of calcium, presumably associated with the gypsum component, is confirmed with evidence of replacement by magnesium. Trends in data suggest initial surface changes which slow ...