75 research outputs found
A study of lunar resources - A preliminary report of surface and some other mining systems Summary report, 22 May 1965 - 1 May 1966
Use of extraterrestrial resources in lunar and planetary exploratio
A lionfish (Pterois miles) invasion has begun in the Mediterranean Sea
Until now, few sightings of the alien lionfish Pterois miles have been reported in the Mediterranean and it was questionable whether the species could invade this region like it has in the western Atlantic. Here, we present evidence from divers and fishermen that lionfish have recently increased in abundance and within a year colonised almost the entire south eastern coast of Cyprus, likely due to sea surface warming. At least 23 different fish are reported of which 6 were removed. Groups of lionfish exhibiting mating behaviour have been noted for the first time in the Mediterranean. Managers need this information and should alert stakeholders to the potential ecological and socio-economic impacts that may arise from a lionfish invasion. Actions could involve incentives to engage divers and fishermen in lionfish removal programmes, as these have worked well at shallow depths in the Caribbean. Given that the Suez Canal has recently been widened and deepened, measures will need to be put in place to help prevent further invasion
Macroscale Drivers of Atlantic and Gulf Menhaden Growth
The identification of anthropogenic and environmental drivers on lengthâatâage of fish stocks is important to understanding ecosystem dynamics and harvest intensity. We evaluated coastwide annual growth of n = 187,115 Atlantic Menhaden (Brevoortia tyrannus ) and n = 299,185 Gulf Menhaden (B. patronus ), using samples collected from the North, Midâ, and South Atlantic from 1961 to 2016 and across the Gulf of Mexico from 1977 to 2016. Using hierarchical models of age 1 growth and age 2 growth, we evaluated a suite of candidate predictors including fishery landings, easterly (U) and northerly (V) wind velocity, river discharge, juvenile abundance, and the Atlantic Multiâdecadal Oscillation (AMO). We found age 2 growth rates were smaller than age 1 growth rates for both species and that Atlantic Menhaden growth rates were 3â4 times greater than Gulf Menhaden. Age 1 growth rate of Atlantic Menhaden was positively affected by landings lagged by one year, indicating a densityâdependent mechanism. In addition, AMO (negative effect), and wind U (positive effect) and wind V (negative effect) in the North Atlantic region were significant factors influencing coastwide age 1 Menhaden growth. Wind V (negative effect) and AMO (positive effect) influenced age 1 Gulf Menhaden growth. No environmental factors were found to have an effect on age 2 Atlantic Menhaden growth, and AMO was the only significant predictor (weak negative effect) of age 2 Gulf Menhaden growth. Fishing pressure was the primary influence on age 1 Atlantic Menhaden growth, whereas age 1 Gulf Menhaden growth was primarily influenced by environmental conditions
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