unlikely toberecovered untillow-grade deposits moreeasily available onlandarenearing exhaustion. GroupIIIOre-bearing siltsandbrines. Massive amounts havebeenfoundin fourdeepbasinsontheflooroftheRedSea,butthehighcostsof extracting iron,zincandcopper makeexploitation uneconomic at present. I...A/40/535 English Page16 GroupIVUsefulminerals occurring aspolymetallic nodules onthe surface ofthesea-bed orunderitatdepthslessthan3metres, mixedwithcalcareous andsiliceous oozes. Thisgroupincludes phosphorite nodules, foundmorefrequently onthecontinental margin, andmanganese nodules, located onthedeepsea-bed in certain partsoftheworld. 40.Theexploitation oftheresources ofthedeepsea-bed wasthesUbject ofmuch discussion andnegotiation duringthepreparation oftheConvention ontheLawof theSea.Usingthetermthe"Area", meaning thesea-bed andoceanfloorand subsoil thereof beyondthelimitsofnational jurisdiction, theConvention declares inpartXIthattheAreaanditsresources arethecommonheritage ofmankind, and itsetsoutprovisions governing activities intheArea.International support for theConvention, although veryconsiderable, waSnotcompletely unanimous. The principles wereaccepted, butsomeoftheobjections fromanumberof industrialized countries concerned theeffects oftheprovisions ofpartXI. 3.Energy fromtheseaandthesea-bed 41.Sincethefirstproduction ofoiloffshore outofsightofland,intheGulf ofMexicoin1947,thetechnical ability toexploit offshore oilandgasfieldshas beenqreatly developed. Thegreatincreases inoilpricesinthe1970sfurther spurred offshore exploration asitmadelocations moreeconomic todevelop. In addition, rapidconsumption ofthisnon-renewable sourceofenergyledtoa vigorous searchfornewdeposits. Thepresent resultofalltheseefforts isa strongoffshore oilindustry that,in1983,produced morethan26percentoftotal worldproduction. Ithasbeenestimated 71thattheannualexpenditure bythe offshore oilindustry isabout$US40billion andthatby1990,production willbe about24million barrels perdayatanannualexpenditure ofover$100billion. 42.Futurecrudeoildiscoveries areexpected tofallroughly intothree categories: onethirdonland,onethirdoffshore ontheoutercontinental shelf andonethirdoffshore indeepwaterandpolarreqions. 81Alargeproportion of theoffshore potential hydrocarbon basinshasbeenidentified aslyingwithinthe 200milesoftheexclusive economic zoneagreedtoundertheConvention ontheLaw oftheSea,andmanynations willbekeentodevelop thedeposits thatmayliein theirnational jurisdictional areas. 43.Offshore coalhasbeenminedformanyyears,usually through theuseof extended coal-seams dipping undertheseafromland. However, significant quantities ofcoalhavebeendiscovered lyingatgreatdepths underthecontinental shelfinmanypartsoftheworldwhich,although inaccessible withpresent-day technology, maybeexploited inthefuture bygasification techniques. 44.Therearealsorenewable energy sources, suchastidalenergy, waveenergy, salinity gradients andseathermal power.Ithasbeenestimated thattheoceans absorbaboutthreequarters ofthesolarenergyreceived bytheplanet. Successfully harnessed, theoceanscouldprOVide enormous andpotentially inexhaustible energysources forthefuture. I...A/40/535 English Page17 4.Sea-borne tradeandshipping 45.Theseaprovides another assetofconsiderahle valuetomankind -itsservice asamediumfortheinternational exchange ofgoodsandpeople. Seatransport is significantly theleastexpensive meansofmovinglargequantities ofcommodities overlongdistances, andsea-borne tradeaccounts forover80percentof international trade byvolume. Notwithstanding theworld-wide recession, in1982 anestimated totalof3,273million tonsofgoodSweremoved bysea,ofwhich 1,793million tonsweredrycargoand1,480million tonswereliquid hydrocarbons. 11Atransport taskofabout13,699billion ton-miles wasperformed bymerchant shipsatanaverage freight costof0.6centsperton-mile (see annexIll,map2). 46.Themajorcommodities transported arecrudepetroleum andpetroleum products, iron-ore, coal,grain,bauxite andalumina, andphosphate inbulk.Ofdrycargoes, about50percentaremixedproducts knownasgeneral cargo. Thisincludes fruit, meatandotherfoodstUffs, manUfactured goods,chemicals andrawmaterials. Shares ofsea-borne tradein1982areshowninthefollowing figure. 47.Theworldmercbant fleetincreased fromabout33,000shipsin1971tosome 37,000shipsin1983.Ofthe1983total,measuring some686million indeadweight tonnage, thedeveloped countries ownedjustover47percent,open-registry countries 29.1percent,developing countries 15.3percentandsocialist countries
**Analysis**
The text discusses the importance of the sea and its resources for human development, including energy production, mineral extraction, and trade. It highlights the significance of the deep sea-bed and its potential for mining, as well as the challenges and controversies surrounding its exploitation. The text also touches on the topic of renewable energy sources, such as tidal and thermal power, and the potential for harnessing them from the oceans.

**Category**
Economic development, Natural resources and environment, Transport and communication, International trade