In 2003, haddock on Georges Bank experienced the largest baby boom ever documented for the stock, with an estimated 800 million new young fish entering the population. With typical annual averages of 50 to 100 million new fish in the last few decades, fisheries biologists have been puzzled by the huge increase and its ramifications for stock management. They have been looking for answers and may have found one - healthy adults.
In a study to be published in the June issue of the Canadian Journal of Fisheries and Aquatic Sciences, Dr. Kevin Friedland and colleagues from NOAA’s National Marine Fisheries Service and the University of Massachusetts suggest that the successful 2003 recruitment year is related to the fall phytoplankton bloom the year before spawning, and to the condition of the adult haddock. Phytoplankton, microscopic marine plants, form the basis of the ocean food web, and are the main source of food for many fish and other animals in the ocean. The fall 2002 bloom was significant, providing a larger than usual source of food for the ecosystem.
“Simply put, having more food to eat gives adult haddock a chance to get into better physical shape to reproduce healthy offspring with a higher chance of survival,” says Friedland, a research scientist at NOAA Fisheries’ Northeast Fisheries Science Center. “We reviewed the commonly applied factors that control recruitment, and found that the fall phytoplankton bloom the year before seems to link parental condition with a good recruitment. We call this new approach the parental condition hypothesis.”
The researchers analyzed various factors that control recruitment, from egg and larval retention, feeding conditions for larvae, size of juveniles in the fall and their estimated hatch dates, prey and time of spawning to circulation patterns and the timing and size of spring and fall phytoplankton blooms. They found that the fall phytoplankton bloom the year prior to spawning and its affect on the condition of adults to be the best supported hypothesis.
Their study suggests that the condition of the adult haddock not only leads to an improved chance to reproduce, but that the adults will produce more eggs of higher quality with higher fertilization rates. Those factors in turn will produce more abundant, larger and potentially better-conditioned offspring with a higher probability of survival to adulthood, which can significantly affect haddock stocks.
Georges Bank haddock have been heavily fished by domestic and foreign fleets over the past 50 years, with shifting patterns of fishery yieldsthat are largely dependent on successful recruitment events. The paradigm that processes affecting mortality during the early life stages determine recruitment has guided research on Georges Bank for decades, with many recent studies suggesting that the formation of each incoming year class of new fish is driven by differing sets of external environmental factors ranging from climate change patterns like the North Atlantic Oscillation to timing of spawning and the feeding environment.
Friedland and colleagues suggest a new paradigm, that the condition of parents affects egg size and fertilization success through the most difficult growth-mortality period early in the haddock life cycle. The bottom line: the number and quality of offspring is more important than the external environmental factors that occur after spawning.
“We need to be able to explain extreme recruitment events for species like haddock, where recruitment is typified by highly unusual circumstances like that in 2003,” Friedland says. “Factors that may be responsible for these large recruitments will help dictate how the haddock resource on Georges Bank is utilized and conserved. This new hypothesis needs to be tested, but it seems to be the only one that explains the 2003 record year class. If it proves true, the implications could be significant.”
NOAA Fisheries Service is dedicated to protecting and preserving our nation's living marine resources and their habitat through scientific research, management and enforcement. NOAA Fisheries Service provides effective stewardship of these resources for the benefit of the nation, supporting coastal communities that depend upon them, and helping to provide safe and healthy seafood to consumers and recreational opportunities for the American public.
The National Oceanic and Atmospheric Administration, an agency of the U.S. Commerce Department, is dedicated to enhancing economic security and national safety through the prediction and research of weather and climate-related events and information service delivery for transportation, and by providing environmental stewardship of our nation's coastal and marine resources. Through the emerging Global Earth Observation System of Systems (GEOSS), NOAA is working with its federal partners, more than 70 countries and the European Commission to develop a global monitoring network that is as integrated as the planet it observes, predicts and protects.
Shelley Dawicki | EurekAlert!
Invasive Insects Cost the World Billions Per Year
04.10.2016 | University of Adelaide
Malaysia's unique freshwater mussels in danger
27.09.2016 | The University of Nottingham Malaysia Campus
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences