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Internal sources and sinks of water, P, N, Ca, and Cl in Lake Kinneret, Israel

1989; Wiley; Volume: 34; Issue: 7 Linguagem: Inglês

10.4319/lo.1989.34.7.1202

1939-5604

Stephen V. Smith, S. Serruya, Y. Geifman, T. Berman,

Fish Ecology and Management Studies

Mass‐balance budgets linked among several materials are used to infer rates of processes affecting Lake Kinneret. Comparisons among budgets reveal the magnitudes of “internal” sources and sinks that cannot be directly inferred from individual budgets. A water budget indicates that ~180 × 10 6 m 3 of sublacustrine spring water plus ungauged surface flow enters the lake annually‐about a fifth the total inflow and two‐thirds as much water as is lost to evaporation. This total ungauged inflow delivers about 90,000 t of Cl yr −1 , nine times the stream input. Ca input from total ungauged flow is about a third the stream input, and the net internal Ca sink in the system is sufficient to precipitate 60,000 t of CaCO 3 yr −1 . Stream delivery of P, mainly as particulate material, is largely sequestered in the sediments (~100 t yr −1 ). At least 1,100 1 yr −1 of N, primarily as NO 3 − delivered by streams, are apparently lost to denitrification, while only 200 t yr −1 are sedimented. Cycling of N and P within the lake dominates over throughput in controlling standing stocks. Vertical mixing within the lake may play a dominating role in this cycling. Cycling of Pin the lake can be regarded as “closed”—a sediment‐water column turnover of materials with only minor hydrographic loss from the system. By contrast, N cycling is “open,” with an important net loss to the atmosphere.