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Here we present first observations, from instrumentation installed on moorings and a float, of unexpectedly low ( < 2 μmol kg⁻¹) oxygen environments in the open waters of the tropical North Atlantic, a region where oxygen concentration does normally not fall much below 40 μmol kg⁻¹. The low-oxygen zones are created at shallow depth, just below the mixed layer, in the euphotic zone of cyclonic eddies and anticyclonic-modewater eddies. Both types of eddies are prone to high surface productivity. Net respiration rates for the eddies are found to be 3 to 5 times higher when compared with surrounding waters. Oxygen is lowest in the centre of the eddies, in a depth range where the swirl velocity, defining the transition between eddy and surroundings, has its maximum. It is assumed that the strong velocity at the outer rim of the eddies hampers the transport of properties across the eddies boundary and as such isolates their cores. This is supported by a remarkably stable hydrographic structure of the eddies core over periods of several months. The eddies propagate westward, at about 4 to 5 km day⁻¹, from their generation region off the West African coast into the open ocean. High productivity and accompanying respiration, paired with sluggish exchange across the eddy boundary, create the “dead zone” inside the eddies, so far only reported for coastal areas or lakes. We observe a direct impact of the open ocean dead zones on the marine ecosystem as such that the diurnal vertical migration of zooplankton is suppressed inside the eddies.

These are the opening remarks  for the 20th International Seaweed Symposium, held in Ensanada, Mexico in 2010.  Professor Thierry Chopin, Pesident of the International Seaweed Association, briefly discusses applications for marine and freshwater macroflaura (algae).

Quickly reducing methane emissions is an important strategy for meeting 2050 climate targets because of the powerful radiative forcing of methane and its relatively short lifetime, but this strategy is undermined by rapidly rising emissions. Agriculture contributes around 40-46% of global methane emissions, and because of rising food production, these emissions are on a path to increase roughly 40% by 2050. Of these emissions, two-thirds are from enteric methane from ruminant livestock, roughly 20% are from rice, and 7% are from managed manure. Although mitigation efforts for agriculture have received less attention, we set forth a credible scenario to decrease these emissions by 54% relative to otherwise likely emissions in 2050 and by 36% compared to present emission levels. Mitigation opportunities include: (1) increasing the feed efficiency of ruminant livestock; (2) rapid development and deployment of promising enteric methane inhibitors; (3) realizing an “Optimistic Trend Projection” for consumption of ruminant meat, which relies more heavily on alternative sources of animal protein; (4) deployment of at least one basic water level drawdown in flooded rice fields plus better offseason management of residues; (5) broad use of at least one method of reducing methane emissions from manure managed in wet form; and (6) reductions in global food loss and waste. Other innovative ideas are also promising. To achieve this mitigation, we suggest in the near-term an internationally coordinated effort to develop “shovel-ready” projects using known mitigation options but structured to encourage innovation and to improve our understanding of how to reduce emissions further. We also suggest a series of internationally coordinated R&D projects and demonstration projects of promising technologies. One key need is a $100 million initiative to have multi-year tests of promising enteric methane inhibitors in at least 20 world locations, and related technical work to bring them to market.

This overview report addresses opportunities for the development of the Pacific Islands’ mariculture sector in general terms. More specific analysis of opportunity in particular

countries is presented in the five accompanying country reports (Cook Islands, Fiji, Papua New Guinea, Republic of the Marshall Islands and Solomon Islands).