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It has been suggested that naturally occurring copper and zinc concentrations in deep seawater are toxic to marine organisms when the free ion forms are overabundant. The effects of micronutrients on the growth of gametophytes of the ecologically and commercially significant giant kelp (Macrocystis pyrifera) were studied in defined media. The results indicate that toxic copper and zinc ion concentrations as well as cobalt and manganese deficiencies may be among the factors controlling the growth of marine organisms in nature.

Multifaceted and diverse energy sources will replace our once massive accumulations of energy reserves. One of these energy sources will be biomass and its natural products; in fact, it will most certainly be one of the essential elements in the complex of the future energy structure. Solar and chemical energy conversion, through biology as a practical energy conversion mechanism, has been extensively documented and reviewed; therefore, this discussion will be restricted to microbial fermentations with specific evaluations of the potentials for microorganisms to synthesize oily hydrocarbons as fermentation products. In biosynthesis, the acyclic hydrocarbons are referred to as fermentation products on the basis of the strict definition of fermentation as being those chemical energy yielding reactions that require organic components as electron acceptors. A generalized fermentation scheme is given in the figure. The scheme is purposely restrictive to emphasize products that are potential fuels. Each of the fermentation products represents a valuable energy form. The most efficient of these fermentation products, in terms of cost of production, cannot be fairly evaluated at this time because of the differences in cell cultivation requirements, product recovery, and most importantly, since many of these products via microbial fermentations are not yet sufficiently developed for commercial consideration. With increasing awareness of microorganisms which grow well or adapt to marginal, extreme or waste environments (taking into account the benefit value of these environments and the rising expenses of waste treatment) the distinct probability exists that the production costs in developing fermentation systems for fuel will become increasingly feasible and attractive. Although the compounds listed in the figure are acceptable fuels and are accessible through microbial processes, the obvious selection of a biochemical fuel for development cannot be determined at this time because not all systems have been adequately investigated. The competitive readiness of the different fermentation systems and the economics of producing each product as they become developed will automatically map out our course of action in years to come

Ruminants are responsible for a large proportion of agricultural greenhouse gas emissions in the form of methane. This can be managed. It is a global initiative to increase productivity of the livestock sector to meet a growing population, but with emphasis on decreasing enteric methane to achieve emissions targets. We investigated the marine red macroalga (seaweed) Asparagopsis taxiformis as a feed ingredient to fundamentally eliminate enteric methane in beef cattle fed a high grain diet and provide evidence of improved livestock production performance. Asparagopsis was included in the feed of Brahman-Angus cross steers at 0.00%, 0.05%, 0.10%, and 0.20% of feed organic matter. Emissions were monitored in respiration chambers fortnightly over 90 d of treatment, steers were weighed weekly prior to feeding, feed intake monitored daily, rumen fluid samples collected in conjunction with respiration chambers for assessment of rumen function, feces were collected for bromoform residue analysis, and meat, organ, and fat were collected post slaughter for residue analysis and sensory evaluation. Steers receiving 0.10% and 0.20% Asparagopsis demonstrated decreased methane up to 40% and 98%, and demonstrated weight gain improvements of 53% and 42%, respectively. There was no negative effect on daily feed intake, feed conversion efficiencies, or rumen function, and no residues or changes in meat eating quality were detected. Commercial production of Asparagopsis could create new economies, and with low inclusion rates of this seaweed in ruminant diets the industry has the potential to revolutionize management of greenhouse gas emissions across the ruminant livestock sector with complementary benefits to the environment, and economy of the wider agriculture sector.

The Maine sea urchin fishery is a classic boom–bust fishery in which efforts to sustain the resource failed despite the creation of a co-management system. We report on ethnographic work undertaken to assist in the development of a fine scale model of the natural system of this fishery. The development of the natural system model required understanding the key linkages between the biology and ecology of the sea urchin and the behavior of fishermen. Information was gathered from the primary scientific literature and from interviews with sea urchin industry members and scientists. Urchin–kelp interactions at a very fine scale create patchy, almost sedentary aggregations of urchins. Settlement of larval urchins appears to be ubiquitous; however, after settlement patches of urchins operate as nearly independent demographic units. In the short term – months to several years – the abundance of urchins in any patch and the spatial dynamics within these patches are determined largely by the actions of fishermen. Consequently, the resource can be characterized as a dynamic fitness landscape in which the spatial structure of urchin patches is the principal determinant of fishermen’s harvesting strategies and fishermen’s activities are the principal determinant ofthe spatial structure of urchin patches.While doing the interviews for the natural system model, we developed a fine scale alternative to the usual theoretical explanation of overfishing. The scale of managementin the fishery occurs at a much broader scale than the demographically relevant scale of urchin patches. This results in a mismatch of ecological and management scales that leave each patch in the fishery in an open access state, resulting in a very fine scale form of serial overfishing that removes, piece-by-piece, discrete, local aggregations of sea urchins.