Rockfish Recruitment and Ecosystem Assessment

Spring 2011 California Current Ecosystem Survey. The spring 2011 California Current Ecosystem (CCE) survey was conducted aboard one NOAA research vessel and a chartered fishing vessel. The NOAA ship Bell M. Shimada (March 23-April 27) covered the area off of the west coast of US from Cape Flattery, Washington to San Diego, California with most of the stations off California located within the area from San Francisco to San Diego (CalCOFI lines 63.3 to 93.3 from March 27 to April 25). The F/V Frosti (March 26-April 28) covered the area from San Francisco to San Diego, California (CalCOFI lines 61.7 to 95, data collected April 1-26). Within the CCE survey the Shimada occupied the primary CalCOFI lines, 76.7 to 93.3, from April 10 to 25 for the spring CalCOFI cruise. During the CCE and the CalCOFI surveys, CalVET tows, Bongo tows, CUFES and trawls were conducted aboard both vessels. Data from both CCE and CalCOFI surveys were included in the estimation of spawning biomass of Pacific sardines.

Sardine Biomass Survey. Eighty four primary stations were plotted on the survey track with an approximate spacing of 20 - 40 nautical miles. At each station the following activities were performed: a. Deployment of a Seabird CTD down to 200 meters, bottom depth permitting. The self-contained CTD collected depth, temperature, conductivity and oxygen data. b. Standard Pairovet cast down to 70 meters depth deployed concurrently with the CUFES system. c. A CalBOBL (CalCOFI Bongo) standard oblique plankton tow with 300 meters of wire out, depth permitting, using paired 505 µm mesh nets with 71 cm diameter openings. The technical requirements for this tow were: Descent wire rate of 50 meters per minute, held at terminal depth for 30 seconds and retrieved at a wire rate of 20 meters per minute. All tows with ascending wire angles lower than 38° or higher than 51° in the final 100 meters of wire were repeated. Additionally, a 45° wire angle was closely maintained during the ascent and descent of the net frame. d. Standard meteorological data including SST, wind speed and direction, wave height and direction, cloud cover, relative humidity, air temperature and barometric pressure. e. During all transits between stations continuous measurements were made of pelagic fish eggs (CUFES) and acoustic targets using the EK-60. f. A 264 Nordic Rope Trawl with 3.0 meter² foam core doors was towed on the surface at night for a duration of thirty minutes. The 264 NRT was modified for surface trawling with Polyform floats attached to the head rope and trawl wings. The trawls have been modified with marine mammal excluder devices (MMED) to eliminate any possibility of catching marine mammals. Although the probability was very low that the gear being lowered into the water on station will interact with any marine mammals, a marine mammal watch was initiated 30 minutes before arriving on station. If any marine mammals were detected in the area, operations were suspended and the station location moved.

TZCF Oceanographic Survey (SE1505). Oceanographic data were collected along the 159W and Meridional from 26° 30'N-32° 30'N. CTD casts were conducted at predetermined stations. CTDs were equipped with oxygen sensors and fluorometers, and chlorophyll and nutrients were measured at discrete depths. Biological backscatter was monitored using the multifrequency EK60 echosounder system operating at 38, 70, 120, and 200 kHz.

Kona Integrated Ecosystem Assessment Survey (SE1401, EK60). This cruise accomplished the following objectives: Oceanographic data were collected from a total of 6 CTD casts and continuous TSG measurements along a predefined grid off the west coast of Hawaii to assess the influence of physical dynamics on the region's biological productivity. CTD-mounted fluorometer measurements were carried out by two fluorometers. Biological backscatter was monitored using the EK60 echosounder system, both during trawl operations and along 7 acoustic transects (including at least one daytime and one nighttime transit of each transect). One nighttime oblique mid-water trawl was conducted prior to the net being damaged beyond repair by contact with the seafloor. Four casts of a DIDSON imaging sonar were conducted to collect high resolution information on the density of high sonic scattering layers. An ROV was deployed 5 times to investigate acoustic scattering layers and adjacent layers. Deep handline jigging was accomplished during day and night to investigate scattering layer macrofauna. Data on cetacean distribution, school size, and school composition were collected via daytime visual surveys on 9 days of transects coupled with several days of small boat survey effort. Two HARP units were deployed for passive autonomous detection of cetaceans and several sonabuoys were also deployed during daytime operations for cetacean detection and identification.

Mesophotic coral environment monitoring and habitat surveys at the Main Hawaiian Island Chain (SE1006, EK60). The goals of the cruise were to collect a variety of data to assess the status of mesophotic corals in waters between the islands of Maui, Kahoolawe, Lanai, and Molokai. Camera surveys of corals and fish were conducted by a live feed video camera attached to a Towed Optical Assessment Device (TOAD). Three mooring, consisting of temperature and current meters, were recovered. Three pairs of Tidbit temperature loggers were deployed. CTD casts were conducted and light profiles taken at predetermined stations at midday. Mixed-gas dive operations were conducted to assess coral communities and the presence of fish, aided with cameras. Sand and gravel samples were taken for amphipod analysis. Biological backscatter were recorded using an EK60 echosounder system operating at 38, 70, and 120 kHz along predetermined transects.

Oceanographic Survey in waters of the Northern Mariana Islands, Guam, and Micronesia (SE1003, EK60). The goals of the cruise were to collect acoustic backscatter and oceanographic data at the vicinity of CNMI, Guam, and in the northern part of Micronesia. Data collected consisted of CTD casts, trawl samples, and continuous monitoring of currents and biological acoustic backscatter. CTD cats were conducted at predetermined stations. CTDs were equipped with oxygen sensors and fluorometers, and water was sampled at discrete depths during each cast for nutrients and chloropigment determinations. Trawl operations were conducted at predetermined stations using an Isaacs Kidd midwater trawl at depths of the shallow sound scattering layer. Currents were continuously monitored using an RD Instruments Acoustic Doppler Current Profiler (ADCP) operating at 75 kHz frequency. Biological backscatter was recorded using an EK60 echosounder system along predetermined transects, operating at 38, 70, and 120 kHz frequencies.

Leeward Oahu Pelagic Ecosystem Characterization (LOPEC-1) (SE1703, EK60). The first primary component of LOPEC-1 on SE1703 was to perform a midwater trawl and bongo net survey from the Oscar Elton Sette to compare to a series of trawl and bongo net surveys from 1951-1978 off leeward Oahu, henceforth referred to as the baseline surveys. The baseline surveys estimated fish composition and abundance for 4 different components of the pelagic community, notably the mesopelagic fish assemblage, shorefish larvae, tuna larvae, as well as a suite of zooplankton taxa from 2 forage availability studies and an early trawl survey. Comparison of current composition and abundances to the baseline composition and abundances after 39-66 years will be a valuable scientific finding to ascertain how the pelagic ecosystem has changed, or not, over that extended time period. The sampling gears used in the baseline surveys from 1951-1978 are 10’ Isaacs-Kidd midwater trawl (IKMT), Cobb trawl, and 70cm bongo nets, all of which are available and deployable on Oscar Elton Sette. The second primary component of LOPEC on SE17-03 was to establish a time series of micronekton and plankton for the leeward Oahu area for ecosystem monitoring. Some operations from the baseline comparison component will be part of the new time series with additional surveys of plankton using other sampling gear such as ring nets and other configurations (different mesh sizes) of bongo nets during both the daytime and the nighttime.

2013 Joint U.S.-Canada Integrated Acoustic and Trawl Survey of Pacific Hake and Pacific Sardine (SaKe 2015) (SH1507, EK60). The 2015 SaKe survey will span the west coasts of the U.S. and Canada from approximately lat 32.8°N (San Diego) to approximately lat 54.65°N (Dixon Entrance, Canada). Eastern and western extents will primarily range from the 20-m isobath or as close to shore as is safely navigable, to either the 1,500-m isobath or a point 35 nmi west of the inshore waypoint, whichever is farther offshore. The primary goal of the survey is to estimate the biomasses, distributions, and biological compositions of populations of Pacific hake and CPS using data from an integrated acoustic and trawl survey off the west coasts of the U.S. and Canada from approximately San Diego, California (lat 32°48.02’N) to the Dixon Entrance, Canada (lat 54°39.00’N). Besides Pacific sardine, the other CPS of interest for the SWFSC are those comprised in the Pacific Fisheries Management Council Fisheries Management Plan (PFMC, 2011) including: Northern anchovy (Engraulis mordax), Pacific Mackerel (Scomber japonicus), Jack Mackerel (Trachurus symmetricus). The NWFSC and SWFSC are interested in all species of euphausiids found within the U.S.’ West Coast EEZ. The current sampling resolution will probably not allow for a comprehensive assessment of all anchovy sub-populations. In particular, those residing in the Southern California Bight and off the Columbia River plume might require additional effort given their patchy distribution. SaKe 2015 will continue to monitor the populations of Ecosystem Component Species (ECS; PFMC, 2011), in particular Pacific Herring (Clupea pallasii). Continuously sample multi-frequency acoustic backscatter data using the ship’s Simrad EK60 scientific echosounder system. These data will be used to estimate the distributions and abundances of hake and the CPS assemblage. Conduct daytime trawling to classify observed backscatter layers to species and size composition and to collect specimens of hake and other organisms. Conduct nighttime (i.e., between sunset and sunrise) surface trawling to collect specimens of coastal pelagic fishes (CPS) and other organisms. These data will be used to classify CPS backscatter to species and their size distributions. Nighttime sampling operations will conclude in time for the ship to resume running east-west acoustic transects by sunrise. Image fish using a portable X-radiograph machine for the purpose of target strength modeling and estimation. Collect a variety of other acoustic, biological, and oceanographic samples relevant to hake and CPS distributions. These data are vital for the surveys and assessments of hake and CPS. Continuously sample sea-surface temperature, salinity, and chlorophyll-a using the ship’s thermosalinograph and fluorometer. These data will be used to estimate the physical oceanographic habitats for each target species. Continuously sample air temperature, barometric pressure, and wind speed and direction using the ship’s integrated weather station. Continuously sample pelagic fish eggs using the Continuous Underway Fish Egg Sampler (CUFES). The data will be used to estimate the distributions and abundances of spawning hake, and multiple CPS. Sample profiles of temperature and salinity using a combination of an underway conductivity-temperature-depth (CTD) system during the day or a standard CTD system with water-sampling rosette and other instruments at nighttime stations, as time allows. Sample plankton using a Vertical Ring Net net at nighttime stations, as time allows. These data will be used to estimate the distribution and abundance of ichthyoplankton and zooplankton species. Continuously sample multi-frequency acoustic backscatter data using the ship’s Simrad ME70 multibeam echosounder system, synchronized and configured to not interfere with the EK60s. Optically verify CPS backscatter while underway conducting acoustic transects,

Cetacean Ecology Survey at North Western Hawaiian Islands (SE1303, EK60). The goal of the cruise was to collect data on the abundance, distribution, stock structure, and habitat of cetaceans in the Papahānaumokuākea Marine National Monument (PMNM) using 7 integrated operations. These operations included visual observations, passive acoustic monitoring, photo-identification, biopsy sampling, satellite tagging, small boat surveys, and oceanography (CTD, Chlorophyll, XBT, and surface samples). A High-frequency Acoustic Recording Package (HARP) was recovered during the cruise.