228 • Marine Minerals: Exploring Our New Ocean Frontier 



Box 6-A. — ICES — International Council for Exploration of the Sea 



The International Council for Exploration of the Sea was set up in the mid-1970s primarily because of 

 concerns over the environmented effects of sand and gravel mining in the North Sea. Three reports were is- 

 sued in 1975, 1976, and 1979. Each report described the current mining operations country by country, as 

 well as the environmentzJ impacts avoided/encountered. The countries participating are the United King- 

 dom, Netherlands, Denmark, Federal Republic of Germany, Freince, Sweden, Norway, Ireland, United States, 

 Belgium, and Finland, Based on the accumulated experience, a series of recommendations were drawn up 

 and set out in the second Report of the ICES Working Group on Effects on Fisheries of Marine Sand and 

 Gravel Extraction: 



Member countries should collect and submit maps for all areas of potential dredging activity showing: 



a), the distribution of different types of sediment, bathymetry, etc. 



b). relevant fishing grounds, spawning areas, nursery areas, etc. 



Additionally, more research on biological, chemical and physical effects was encouraged and the need 

 for an environmental impact statement before prospecting or licensing was highlighted. 



The three ICES reports conclude that the method selected for sand and gravel mining determines the 

 direct and indirect impacts to bottom fauna and the final condition of the seafloor. There are three eJternative 

 mining methods: 



1. Extraction in a restricted cirea, deep into the seabed, with a stationary hopper dredger; the result will be 

 a deep hole (as much as 230 feet) in the bottom. Such pits will not naturally be backfilled with sediment. 



2. Extraction over a wide area with trailing hopper dredgers; this will result in only removal of the top 

 8 inches. 



3. Extraction over a relatively large area with stationary seaworthy dredging equipment; the sea bottom 

 is lowered over the area by about 33-50 feet. 



For sand dredging off the Netherlands coast, where sand is found in thick layers, a shallow lowering of 

 the sea bottom over a wide area is preferred'. Bottom composition and structure both before and after dredg- 

 ing remain similar. Although there would be destruction of the bottom fauna throughout the area mined, 

 such effects are likely to be temporary. The recovery of the flora and the fauna should occur quickly because 

 the colonizing substrate is unchanged. 



If deep excavation is used in water depths greater than 50 feet, the pits will generally not backfill with 

 sand because litde transport takes place at these depths. An example of the impacts associated with deep exca- 

 vation mining exists near the U.K. coast off Hastings, where gravel mining produced a pockmarked land- 

 scape in a previously good trawling area; here, bottom-trawling gear can no longer be used.^ 



From the many studies on the effects of marine aggregate dredging, it is evident that initial impacts can 

 vary from minimeJ to severe and that disruptions range from short to long term. The sensitivity of the area 

 involved determines the impact. 



Belgium has adopted the ICES protocol and has designated all of its continental shelf as belonging to 

 one of four zones that control the exploitation and extraction of sand offshore: 



• Zone I: Navigation areas. Extraction prohibited. 



• Zone 2: Fishing Grounds. In view of their importance as spawning and nursery areas, this zone is 

 prohibited for exploitation and extraction. 



• Zone 3: Southern part of the Belgian continental shelf. Mining allowed when ecological monitoring 

 is carried out. 



• Zone 4: Northern part of the Belgian continental shelf. Extraction allowed after preliminary monitor- 

 ing, with continuous ecological monitoring during extraction. 



Canada is in the process of developing regulations for offshore mining' and is considering similar designations. 



'International Council for the Exploration of ihe Sea, Marine Environmental Quality Committee, Report of the ICES Working Group on Effects on 

 Fisileries of Marine Sand and Grave] Extraction, (Charlottenlund, Denmark: ICES, 1979). 



'S.J. de Groot, "An Assessment of the Potential Environmental Impact of Large-Scale Sand-Dredging for the Building of Artificial Islands in the 

 North Sea," Oceajj Management, No. 5 (1979), pp. 211-232. 



'David Pasho, Canada Oil and Gas Lands Administration, OTA Workshop on Environmental Concerns, Washington, D.C., Oct. 29, 1986. 



