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Since 2000, virtually every major assessment of ocean policy has called for implementing an ecosystem approach to managing marine resources, yet crafting such an approach has proved difficult. Ecosystems today exhibit little of the abundance and complexity found in the past, and populations of over‐fished species have declined dramatically world‐wide, yet historical evidence has been difficult to assimilate into complex ecosystem models. Here, we look to the testimony of Gulf of Maine fishermen for insights on the abundance of Atlantic cod (Gadus morhua) and the environment that once supported such large numbers of them. Using logbook data from Frenchman’s Bay, Maine, and other New England communities at the time of the Civil War, we estimate cod landings in the Gulf of Maine in 1861, establish a population structure for cod at that time, and map the geographical distribution of fishing effort of a fleet that minimized risk and cut expenses by fishing inshore where cod and bait species were plentiful. Log entries list the pelagic and bottom‐dwelling invertebrate species these fishermen used for bait, when and how they acquired it, and what species they looked for in the water to signify the presence of cod. Ranked descriptions of both cod and bait abundance were found to be statistically significant indicators of cod catch. Frenchman’s Bay fishermen 140 years ago provided a minimum set of ecosystem requirements for abundant cod, conditions that may inform management plans aimed at restoring both the species and the Gulf of Maine marine ecosystem.

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In plant metabolism glycerol phosphate must be produced for the synthesis of various phospholipids, sulfolipids, galactolipids, and triglycerides. The metabolic reaction in leaf tissue of higher plants for glycerol phosphate synthesis is catalyzed by a DHAP2 reductase which has been partially purified from spinach leaves and castor bean endosperm, and which catalyzes the reduction of DHAP at pH 7.0 using NADH as the reductant (6,17 No. 12290. 2Abbreviations: DHAP, dihydroxyacetone phosphate; ME, mercaptoethanol; PVPP, polyvinylpolypyrrolidone. metabolism must be highly controlled, as is expected of compounds and enzymes at metabolic branch points.A number of free living algae produce glycerol as a major product of photosynthesis rather than accumulate starch or sucrose. Zooxanthellae, symbiotic, unicellular algae in the polyps of reef building corals and other marine invertebrates, excrete to their host up to 40% of their photosynthate as glycerol (14, 15).The halotolerant alga, Dunaliella tertiolecta (5,20) and Chiamydomonas (1 1)

Homogenates from the salt-excreting leaves of the mangroveAvicennia nitidawere subjected to differential centrifugation and investigated for adenosine triphosphatase activities. At pH 6.73 a salt stimulation with peaks at three different sodium to potassium ratios could be demonstrated above the activity due to NIg2+ ions. The stimulation by sodium and potassium depends on the ionic strength of the test medium, higher salt concentrations being inhibitory. The leaves of Avicennia excrete salts from special glands. Uptake of potassium in leaf pieces of the species Avicennia marina has been investigated (13). The optimum absorption of K+ is a function of the concentration of Na+ in the medium. We are inclined to interpret this dependence as potassium uptake coupled to sodium extrusion.With the above considerations in mind, we started a search for ATPases dependent upon the Na:K ratio in leaves of Avicennia. This paper presents evidence that such enzyme activities are present and are dependent upon the ionic strength of the assay medium. Difficulties were encountered in developing a preparation procedure, as well as in cultivating the plants under laboratory conditions. At this stage of development it may be useful if such technical difficulties are discussed, since others have sought evidence for the occurrence of (Na+ + K+)-dependent ATPases without success (1, 5, 6). MATERIALS AND METHODSPlants. Small trees of Avicennia nitida Jacq. were cultivated together with other mangroves in a growth chamber with 14 hr of light and 10 hr of darkness. The light was from mixed cool white and warm white fluorescent tubes, giving between 20,000 and 30,000 lux at the level of the branches used. The day temperature was regulated at 24°and the night temperature at 160.The medium was fundamentally Johnson's solution and contained 6 mm KNO3, 4 mm Ca(NO3)2, 2 mm (NH4)H2PO4, 1 mM MgSO4, 0.04 mm FeSO4 in 0.08 mm Na3-citrate, and trace amounts of B, Mn, Zn, Cu, Mo, and Co. The medium was made up in filtered sea water and deionized water to give the required range of total salinity.The media were originally made up with 50% sea water. In order to increase growth, the plants were then transferred to a medium with only the nutrient salts in deionized water. After a month, a group of plants of the genus Aegialithis were attacked by root fungi. In order to control this infection and keep it from spreading, the plants were returned to 50% sea water, which stopped the growth of the fungus. After the pest had been controlled, the main group of Avicennia plants were kept with a salinity of 25% sea water. A few plants were grown with only nutrients in deionized water. It should be noted that the Avicennia plants were never actually attacked by the fungus.Preparation of ATPase. In their studies of the ATPase of sugar 169 www.plantphysiol.org on May 11, 2018 -Published by Downloaded from