Reproductive biology of blue marlin (Makaira nigricans) in the western Pacific Ocean

The reproductive biology of blue marlin (Makaira nigricans) was assessed from 1001 fish (ranging from 121 to 275 cm in eye-to-fork length; EFL) caught by Taiwanese offshore longliners in the western Pacific Ocean from September 2000 to December 2001 and from 843 gonad samples from these fish, The overall sex ratio of the catch was approximately 1:1 dur ing the sampling period, but blue marlin are sexually dimorphic; females are larger than males. Reproductive activity (assessed by histology), a gonadosomatic index, and the distribution of oocyte diameters, indicated that spawning occurred predominantly from May to September. The estimated sizes-at-maturity (EFL50) were 179.76 ±1.01 cm (mean ±standard error) for females and 130 ±1 cm EFL for males. Blue marlin are multiple spawners and oocytes develop asynchronously. The proportion of mature females with ovaries containing postovulatory follicles (0.41) and hydrated oocytes (0.34) indicated that the blue marlin spawned once every 2–3 days on average. Batch fecundity (BF) for 26 females with the most advanced oocytes (≥1000 μm), but without postovulatory follicles, ranged from 2.11 to 13.50 million eggs (6.94 ± 0.54 million eggs). The relationships between batch fecundity (BF, in millions of eggs) and EFL and round weight (RW, kg) were BF = 3.29 × 10 –12 EFL5.31 (r2 = 0.70) and BF = 1.59 × 10–3 RW 1.73 (r2= 0.67), respectively. The parameters estimated in this study are key information for stock assessments of blue marlin in the western Pacific Ocean and will contribute to the conservation and sustainable yield of

Restormel Fish Counter Annual Report 2002

This is the Restormel Fish Counter, Annual Report 2002 produced by the Environment Agency South West Region on March 2003. The report presents the daily upstream counts of migratory salmonids recorded on the River Fowey at Restormel Weir fish counting station (SX 107 613) in 2002. Data contained within this report covers the period of the commercial migratory salmonid net buy-back scheme and the National Spring Salmon Bylaws. The fish counter at Restormel is a resistivity based system (Logie 2100A - Aquantic limited) and is installed on the weir at Restormel approximately 2 km upstream of the tidal limit. The run pattern observed for salmon and sea trout in 2002 was generally consistent with that of previous years. The upstream salmon / large sea trout count for 2002 was 1804.

Restormel Fish Counter Annual Report 2005

This is the Restormel Fish Counter, Annual Report 2005 produced by the Environment Agency South West Region on March 2006. The report presents the upstream counts of migratory salmonids recorded on the River Fowey at Restormel weir fish counting station (SX 107 613) over the period March 2005 to February 2006 inclusive. Data contained within this report covers the period of the commercial migratory salmonid net buy-back scheme and the National Spring Salmon Byelaws (from 2 March to 15 June Inclusive). The minimum upstream salmon estimate for 2005 was 1046, this is the second highest count recorded over the past 11 years. The total sea trout count (10448) was 8% higher than 2004 (9608). This overall increase in the salmon and sea trout counts, together with the consistency of the numbers of fish returning over recent years suggests that measures designed to protect salmonid stocks in the River Fowey are working.

Restormel Fish Counter Annual Report 2006

This is the Restormel Fish Counter, Annual Report 2006 produced by the Environment Agency South West Region on March 2007. The report presents the upstream counts of migratory salmonids recorded on the River Fowey at Restormel weir fish counting station (SX 107 613) over the period March 2006 to February 2007 inclusive. Data contained within this report covers the period of the commercial migratory salmonid net buy-back scheme and the National Spring Salmon Byelaws (2 March- 15 June inclusive). The minimum upstream salmon estimate for 2005 (1046), over the period July 2005 to February 2006, was 20% lower than that recorded over the same period in 2004 (1301). However, this is the second highest count recorded over the past 11 years. The total sea trout count (10448) was 8% higher than 2004 (9608). The number of salmon and large sea trout was lower than average in 2005. However, the overall numbers of adult salmon and sea trout returning have been increasing year on year since 1997. This overall increase in the salmon and sea trout counts, together with the consistency of the numbers of fish returning over recent years suggests that measures designed to protect salmonid stocks in the River Fowey are working.

Cruise report: regional assessment of ecosystem condition and stressor impacts along the northwestern Gulf of Mexico Shelf. NOAA Ship 'Nancy Foster' NF-11-07-RACOW (August 8-16, 2011)

This cruise report is a summary of a field survey conducted along a portion of the U.S. continental shelf in northwestern Gulf of Mexico (GOM), at navigable depths along the coastline seaward to the shelf break (~100m) from about 89°30' W to 95°28' W longitude, August 8 – 16, 2011 on NOAA Ship Nancy Foster Cruise NF-11-07-RACOW. Synoptic sampling of multiple ecological indicators was conducted at each of 34 stations throughout these waters using a random probabilistic sampling design. The original study design consisted of 50 stations extending from the Mississippi delta all the way to the U.S./Mexican border, but vessel failures precluded sampling at 16 stations within the western-most portion of the study area. At each station samples were collected for the analysis of benthic community structure and composition; concentrations of chemical contaminants in sediments and target demersal biota; sediment toxicity; nutrient and chlorophyll levels in the water column; and other basic habitat characteristics such as salinity, temperature, dissolved oxygen, turbidity, pH, sediment grain size, and organic carbon content. Other indicators, from a human-dimension perspective, were also recorded, including presence of vessels, oil rigs, surface trash, visual oil sheens in sediments or water, marine mammals, or noxious/oily sediment odors. The overall purpose of the survey was to collect data to assess the status of ecosystem condition and potential stressor impacts throughout the region, based on these various indicators and corresponding management thresholds, and to provide this information as a baseline for determining how such conditions may be changing with time. While sample analysis is still ongoing, some preliminary results and observations are reported here. A final report will be completed once all data have been processed.