pristine or unspoiled condition. It requires that theee ecosystems be protected in such a way as to maintain them as much as possible in their 14.8 /Proposed Medium-Term Plan for the period 1992-1997, Major proyramme IV, Intelnational economic co-operation for development, Programme 16, Environment (A/45/6), p. 9, pare. 16.24. 149/ Ses, e.g. “Wnter: the finite resource”, lLKkUWhf;iD, volume 21, I! mber 1, March 1990, y. 14. 150 /Article ti entitled “Equitable nnd reasonable utilization and Participation”, pnrn. 1, second mnt.enca, reproduced in subsection 1 above. 1511 The obl iqetion t-0 protect. the ecosystems of international watercourse[s ] [ :;yst.sms] is thus n general application of the principle of precautionary act. ion, disc:rrsst~d blow (see note 176 nnd accompanying text below). .’ 14Y -natural state. Together, proteotion and preservation of aquatic ecosystema help to ensure their continued viability aa life support 8yatem6, thue providing an eeeential basic for sustainable development, 3.521 (4) In requiring that watercourse States act “individually or jointly”, article 22 recognieee that in some cagea it will be neceesery and appropriate that watercourse States co-operate, on an equitable basis, to protect and preerve the ecosystems of international wateroourss[s] [eyeteme]. The obligation to take such action “jointly” is a specific application of certain general obligations contained in Part IT of the draft articles. Thus article 6 requires that watercourse States “participate in the , , , protection of an international watercourse [bystem] in an equitable and reasonable manner”, and provides that “[s]uch participation includes . . . the clluty to co-operate in the protection and development” of international watercouree[ 8 ] [syeteme]. l53/ In addition, article 9 provides that watercouroe State8 shall co-operate, inter_elia, “in order to attain . . . ac¶equate protection of an internetionel watercourse [eyatem].” The requirement of article 22 that watercouree States act “individually or jointly” is therefore to be understood
**Analysis**
The text discusses the protection and preservation of international watercourses and their ecosystems, emphasizing the importance of maintaining them in their natural state. It highlights the obligation of watercourse States to act individually or jointly to protect and preserve these ecosystems, citing specific articles from the draft articles on the law of the non-navigational uses of international watercourses. The text also mentions the principle of precautionary action and the concept of sustainable development. Based on this, it can be inferred that the category should be related to the environment and natural resources.

**Category**
Natural resources and environment