A census of maerl beds in Irish waters

Abstract

1. Records of maerl beds in Irish waters were compiled from the following sources: Admiralty Charts, published/unpublished ecological/geological accounts, and personal communications/observations. 2. Geographic and depth distributions of maerl records in Irish waters are discussed. Two main areas, Galway Bay–Connemara and South West Ireland, were identified as harbouring the highest concentrations of confirmed records, with maximum depth of confirmed records being approximately 25–30 m. 3. Deposits shown as ‘crl’ markings on older Admiralty Charts may refer to maerl and are situated at greater depths (to 95 m) and are further offshore than confirmed deposits (to 32 m), the latter being based on more recent observations. 4. Although the precise number of maerl beds in Irish waters cannot be assessed from the available records, the minimum number of larger beds (>1 km2), based on confirmed records only, is 35–40 beds located in 18 areas. In addition, along the south‐west coastline numerous smaller spatial aggregations (as small as 1–5 m2) occur. Copyright © 1999 John Wiley & Sons, Ltd.

Biodiversity and habitat mapping of Menorca Channel (western Mediterranean): implications for conservation

“…The rest (calcareous algae L. corallioides and P. calcareum, the crustaceans Scyllarus arctus, Scyllarus pygmaeus, Homarus gammarus, Maja squinado, Palinurus elephas and Scyllarides latus and the elasmobranch Rostroraja alba) are considered species whose harvesting and exploitation should be regulated and subject to management measures (Table 6). L. corallioides and P. calcareum are not commercially exploited in this area, as it happened in some zones of the Atlantic De Grave and Whitaker 1999). However, their extraction during fishing activities (discard species) results in the fragmentation, dispersion and modification of the biological community (Barberá et al 2003).…”

Algal Proteins: Extraction, Application, and Challenges Concerning Production

“…There are currently no restrictions on harvesting quantities in Ireland, nor are there any restrictions on harvesting times. The only exception to this is for maërl due to its extremely slow growth rate (0.6–1.5 mm per annum) [ 245 ]. However, the future implementation of mechanical harvesting methods will likely require a review of existing legislation to ensure appropriate access rights and sustainable harvesting yields are maintained.…”

Chemical and physical features of living and non-living maerl rhodoliths

“…However, this only applies to Atlantic ex ploited maerl and not to any rarer species or non-commercially exploited maerl (Barbera et al 2003). Data regarding the distribution of Irish maerl beds has been the topic of a recent report (De Grave & Whitaker 1999), which concludes that 65 to 70% of all confirmed maerl beds in Irish waters occur in the Galway-Connemara region, 20 to 25% occur in the southwest region, and the remainder occur along the Donegal coast, with an overall abundance of the order of 3 × 10 6 m 3 of exploitable maerl. With this vast resource, there has been renewed interest in maerl, both commercially and in terms of its ecological importance and conservation needs.…”

“…Interestingly, floridoside has recently been highlighted as a potentially important new anticomplementary agent for use in therapeutic complement depletion (Courtois et al 2008), as a potentially health-promoting prebiotic foodstuff (Ishihara et al 2010), as an antioxidant (Li et al 2010) and in conjunction with isethionic acid as a novel bacterial quorum-sensing inhibitor (Liu et al 2008). Thus, in light of the recent findings highlighting Ireland's significant maerl resource (De Grave & Whitaker 1999) and the apparent abundance of PUFA and floridoside, there is a clear potential for the commercial exploitation of maerl for biomedical, biotechnology and pharmaceutical industries. NLM has been shown to possess similar concentrations of floridoside (and PUFA) and may therefore be a more appropriate option for commercial exploitation.…”

“…It is primarily NLM that is commercially exploited (Blunden et al 1975) and has been collected off the Irish, Cornish and Brittany coasts since the 17th, 18th and 19th centuries respectively (De Grave & Whitaker 1999). It is used as an agricultural fertiliser to increase the pH of acidic soils and also more recently for soil ameliora-tion, as an animal fodder additive, in acid water treatment, in biological denitrification, in drinking water treatment, in toxin elimination and in the pharmaceutical, cosmetics, nuclear and medical industries (Blunden et al 1975(Blunden et al , 1977(Blunden et al , 1997.…”