Global transcriptional responses of the toxic cyanobacterium, Microcystis aeruginosa, to nitrogen stress, phosphorus stress, and growth on organic matter

Whole transcriptome shotgun sequencing (RNA-seq) was used to assess the transcriptomic response of the toxic cyanobacterium Microcystis aeruginosa during growth with low levels of dissolved inorganic nitrogen (low N), low levels of dissolved inorganic phosphorus (low P), and in the presence of high levels of high molecular weight dissolved organic matter (HMWDOM). Under low N, one third of the genome was differentially expressed, with significant increases in transcripts observed among genes within the nir operon, urea transport genes (urtBCDE), and amino acid transporters while significant decreases in transcripts were observed in genes related to photosynthesis. There was also a significant decrease in the transcription of the microcystin synthetase gene set under low N and a significant decrease in microcystin content per Microcystis cell demonstrating that N supply influences cellular toxicity. Under low P, 27% of the genome was differentially expressed. The Pho regulon was induced leading to large increases in transcript levels of the alkaline phosphatase phoX, the Pst transport system (pstABC), and the sphX gene, and transcripts of multiple sulfate transporter were also significantly more abundant. While the transcriptional response to growth on HMWDOM was smaller (5–22% of genes differentially expressed), transcripts of multiple genes specifically associated with the transport and degradation of organic compounds were significantly more abundant within HMWDOM treatments and thus may be recruited by Microcystis to utilize these substrates. Collectively, these findings provide a comprehensive understanding of the nutritional physiology of this toxic, bloom-forming cyanobacterium and the role of N in controlling microcystin synthesis.

A biogeographic asssessment of seabirds, deep sea corals and ocean habitats of the New York Bight: science to support offshore spatial planning

This report provides a compilation of new maps and spatial assessments for seabirds, bathymetry, surficial sediments, deep sea corals, and oceanographic habitats in support of offshore spatial planning led by the New York Department of State Ocean and Great Lakes Program. These diverse ecological themes represent priority information gaps left by past assessments and were requested by New York to better understand and balance ocean uses and environmental conservation in the Atlantic. The main goal of this report is to translate raw ecological, geomorphological and oceanographic data into maps and assessments that can be easily used and understood by coastal managers involved in offshore spatial planning. New York plans to integrate information in this report with other ecological, geophysical and human use data to obtain a broad perspective on the ocean environment, human uses and their interactions. New York will then use this information in an ecosystem-based framework to coordinate and support decisions balancing competing demands in their offshore environment, and ultimately develop a series of amendments to New York’s federally approved Coastal Management Program. The targeted users of this report and the compiled spatial information are New York coastal managers, but other State and federal decision-makers, offshore renewable energy development interests and environmental advocates will also find the information useful. In addition, the data and approaches will be useful to regional spatial planning initiatives set up by the Mid-Atlantic Regional Council on the Ocean (MARCO) and federal regional planning bodies for coastal and marine spatial planning.

Water quality studies of the Delaware River with reference to shad migration

For some time pollution of the waters of the Delaware River by municipal and industrial wastes has been suspected of playing a major role in the decline of the shad fishery. Accordingly, studies were planned to ascertain whether any conditions of water quality caused by stream pollution and harmful or lethal to shad were existant in the waters of the Delaware River during the migration periods of the shad.

Key for the identification of the East African marine fishes to family level

The paper provides key for the identification of the East African marine fishes. Just like in most determination keys this one is based on the "either-or" principle, i.e. there is a single alternatIve at each point. A specimen either fits all the characters recorded, or fails to conform to one or more characters and you should then proceed to the next number, keeping this up until the fish to be identified does fit all the characters.