Lea esta publicación en español: Michael Gutiérrez Santiago: Línea Hidrográfica de Newport, 18 de agosto de 2022
NOAA Teacher at Sea
Michael Gutiérrez Santiago
NOAA Ship Bell M. Shimada
August 12 – August 25, 2022
Mission: Pacific Hake Survey
Geographic Area of Cruise: Coasts of Washington and Oregon
Date: August 18, 2022
Weather conditions from the bridge:
Wind Speed: 13 mph
Science and Technology Log
Newport Hydrographic Line
One way scientists assess the health of our ocean’s ecosystems is to take samples of zooplankton and ichthyoplankton (fish eggs and larvae), both on the surface of the water and at depth. Observations of these plankton can inform us greatly about productivity at the bottom of the food chain, spawning location and stock size of adults, dispersal of larval fish and crabs to and away from nursery areas, and transport of ocean currents.
The Newport Hydrographic (Newport Line) is an oceanographic research survey conducted by NOAA’s Northwest Fisheries Science Center and Oregon State University scientists in the coastal waters off Newport, Oregon.
Researchers have collected physical, chemical, and biological oceanographic metrics along the Newport Line every two weeks for over 20 years. This twenty-plus year dataset helps us to understand the connections between changes in ocean-climate and ecosystem structure and function in the California Current.
Data from the Newport Line are distilled into ocean ecosystem indicators, used to characterize the habitat and survival of juvenile salmonids, and which have also shown promise for other stocks such as sablefish, rockfish, and sardine. These data also provide critical ecosystem information on emerging issues such as marine heatwaves, ocean acidification, hypoxia, and harmful algal blooms.
Barometer of ocean acidification and hypoxia in a changing climate
Global climate models suggest future changes in coastal upwelling will lead to increased incidence of hypoxia and further exacerbate the effects of ocean acidification. The Newport Line time-series provides a baseline of biogeochemical parameters, such as Aragonite saturation state—an indicator of acidic conditions. Researchers can compare this baseline against possible future changes in the abundance of organisms (e.g., pteropods, copepods and krill) sensitive to ocean acidification and hypoxia.
A vertical net is a ring net with a small mesh width and a long funnel shape. At the end, the net is closed off with a cylinder (cod-end) that collects the plankton. It is deployed vertically in the water from a research vessel. It is mostly used to investigate the vertical/diagonal stratification of plankton. This allows the abundance and distribution of mesozooplankton to be determined.
A bongo net consists of two plankton nets mounted next to each other. These plankton nets are ring nets with a small mesh width and a long funnel shape. Both nets are enclosed by a cod-end that is used for collecting plankton. The bongo net is pulled horizontally through the water column by a research vessel. Using a bongo net, a scientist can work with two different mesh widths simultaneously.
Isaacs-Kidd midwater trawl collects bathypelagic biological specimens larger than those taken by standard plankton nets. The trawl consists of the specifically designed net attached to a wide, V-shaped, rigid diving vane. The vane keeps the mouth of the net open and exerts a depressing force, maintaining the trawl at depth for extended periods at towing speeds up to 5 knots. The inlet opening is unobstructed by the towing cable.
What we got?
That’s right, our underway CTD was attacked by a shark.
On a bright and sunny day, the science team decided to launch the underway CTD, but things didn’t go as planned! Retrieving the uCTD back to the ship we saw a big dorsal fin zigzagging close to the uCTD, until we noticed that the uCTD was no longer attached to the line, therefore we had no choice that to cancel the uCTD. You should have seen all of our faces; we couldn’t believe what we saw. We think it could have been a:
CTD stands for conductivity (salinity), temperature, and depth and it enables researchers to collect temperature and salinity profiles of the upper ocean at underway speeds, to depths of up to 500 m. Ocean explorers often use CTD measurements to detect evidence of volcanoes, hydrothermal vents, and other deep-sea features that cause changes to the physical and chemical properties of seawater.