Multispecies larval fish associations: Accident or Adaptation?

1983 ◽  
Vol 40 (6) ◽  
pp. 754-762 ◽  
Author(s):  
Kenneth T. Frank ◽  
William C. Leggett
Keyword(s):  
Coastal Water ◽  
Dominant Species ◽  
Water Mass ◽  
Larval Survival ◽  
Water Masses ◽  
Potential Growth ◽  
Safe Sites ◽  
Demersal Eggs ◽  
Frequency Distributions ◽  
Larval Drift

Capelin larvae (Mallotus villosus) time their period of larval drift to coincide with water masses containing abundant food resources and a reduced predator complex by responding to environmental cues associated with coastal water mass replacement. This persistent, coast-wide phenomenon led us to hypothesize that the initiation of larval drift in species of fishes other than capelin, having similar spawning modes, should be linked to the occurrence of these "safe site" water masses. The abundance of larvae of demersal spawning species, other than capelin, in the nearshore waters of our study site in eastern Newfoundland was highly variable during June–August in 1979 and 1980 and was unrelated to seasonal trends. The abundance of this sympatric noncapelin component of the ichthyoplankton was, however, positively related to both water temperature and larval capelin density, both of which are strongly influenced by coastal water mass replacement, and to the occurrence of conditions favorable to larval survival: "safe sites." The noncapelin larval assemblage was dominated by species having demersal eggs (90% of the total catch in two years) spawned in shallow water, in particular, winter flounder (Pseudopleuronectes americanus), radiated shanny (Ulvaria subbifurcata), and seasnails (Liparis spp.). Weekly size frequency distributions of these three species were dominated by newly hatched larvae. We conclude that the onset of larval drift in these species was also synchronized to the temporally variable occurrence of ecological safe sites for larvae. Three advantages accrue: food levels and potential growth rates would be greatly enhanced, predator density would be reduced, and predation rates would be reduced due to association with the dominant species (capelin) that saturate the predator field. Similar associations between a single dominant species and other much less abundant species appear to be common features of the ichthyoplankton of temperate/boreal regions.

scholarly journals Local Coastal Water Masses Control Heat Levels in a West Greenland Tidewater Outlet Glacier Fjord

2018 ◽  
Vol 123 (11) ◽  
pp. 8068-8083 ◽  
Author(s):  
J. Mortensen ◽  
S. Rysgaard ◽  
K. E. Arendt ◽  
T. Juul-Pedersen ◽  
D. H. Søgaard ◽  
...  
Keyword(s):  
Coastal Water ◽  
Water Masses ◽  
Outlet Glacier ◽  
West Greenland

scholarly journals WATER MASSES CHARACTERISTICS AT THE SANGHIE TALAUD ENTRY PASSAGE OF INDONESIAN THROUGHFLOW USING INDEX SATAL DATA 2010

2015 ◽  
Vol 6 (2) ◽  
Author(s):  
Ivonne M Radjawane ◽  
Paundra P Hadipoetranto
Keyword(s):  
North Pacific ◽  
Water Mass ◽  
Sea Water ◽  
Core Layer ◽  
South Pacific ◽  
New Guinea ◽  
Water Masses ◽  
Coastal Current ◽  
Indonesian Throughflow ◽  
Pacific Water

<p><strong><em>ABSTRACT</em></strong></p> <p><em>Measurement of ocean physical param</em><em>eter</em><em>s using the CTD was conducted by </em><em>deep water expedition </em><em>INDEX-SATAL 2010 (Indonesian Expedition Sangihe-Talaud) in July-August 2010. Th</em><em>e</em><em> </em><em>aim of this </em><em>study wa</em><em>s to</em><em> determine the characteristics of water masses around the Sangihe Talaud Water where the</em><em>re </em><em>wa</em><em>s an entry passage of </em><em> Indonesian throughflow (ITF) </em><em>at</em><em> </em><em>the </em><em>west </em><em>path</em><em>way that passed through the </em><em>primary</em><em> pathway i.e., </em><em>the Sulawesi</em><em> Sea and Makassar Strait and the secondary pathway (east pathway) that passed through the Halmahera Sea. The analyses were performed by the method of the core layer and was  processed with software Ocean Data View (ODV). The results showed that in the Sangihe Talaud waters there was a meeting water masses from the North Pacific and the South Pacific. The water mass characteristics in main pathway through the Sulawesi Sea was dominated by surface and intermediate North Pacific water masses and carried by the Mindanao Currents. While the Halmahera Sea water mass was dominated by surface and intermediate South Pacific water masses carried by the New Guinea Coastal Current that moved along the Papua New Guinea and Papua coast enters to the Halmahera Sea. </em></p> <p><em> </em></p> <p><strong><em>Keywords</em></strong><em>: Index-Satal 2010, Northern Pacific Water Mass</em><em>es</em><em>, Southern Pacific Water </em></p> <em> Masses, Sangihe Talaud</em>

scholarly journals A novel method for tracing coastal water masses using Sr/Ca ratios and salinity in Nanwan Bay, southern Taiwan

2005 ◽  
Vol 65 (1-2) ◽  
pp. 135-142 ◽  
Author(s):  
Chuan-Chou Shen ◽  
Kon-Kee Liu ◽  
Meng-Yang Lee ◽  
Typhoon Lee ◽  
Chung-Ho Wang ◽  
...  
Keyword(s):  
Coastal Water ◽  
Water Masses ◽  
Novel Method ◽  
Southern Taiwan

scholarly journals Water mass distributions and transports for the 2014 GEOVIDE cruise in the North Atlantic

2018 ◽  
Vol 15 (7) ◽  
pp. 2075-2090 ◽  
Author(s):  
Maribel I. García-Ibáñez ◽  
Fiz F. Pérez ◽  
Pascale Lherminier ◽  
Patricia Zunino ◽  
Herlé Mercier ◽  
...  
Keyword(s):  
North Atlantic ◽  
Water Mass ◽  
Water Levels ◽  
Water Masses ◽  
Meridional Overturning Circulation ◽  
Labrador Sea ◽  
Intermediate Water ◽  
North East ◽  
The North ◽  
The North Atlantic

Abstract. We present the distribution of water masses along the GEOTRACES-GA01 section during the GEOVIDE cruise, which crossed the subpolar North Atlantic Ocean and the Labrador Sea in the summer of 2014. The water mass structure resulting from an extended optimum multiparameter (eOMP) analysis provides the framework for interpreting the observed distributions of trace elements and their isotopes. Central Waters and Subpolar Mode Waters (SPMW) dominated the upper part of the GEOTRACES-GA01 section. At intermediate depths, the dominant water mass was Labrador Sea Water, while the deep parts of the section were filled by Iceland–Scotland Overflow Water (ISOW) and North-East Atlantic Deep Water. We also evaluate the water mass volume transports across the 2014 OVIDE line (Portugal to Greenland section) by combining the water mass fractions resulting from the eOMP analysis with the absolute geostrophic velocity field estimated through a box inverse model. This allowed us to assess the relative contribution of each water mass to the transport across the section. Finally, we discuss the changes in the distribution and transport of water masses between the 2014 OVIDE line and the 2002–2010 mean state. At the upper and intermediate water levels, colder end-members of the water masses replaced the warmer ones in 2014 with respect to 2002–2010, in agreement with the long-term cooling of the North Atlantic Subpolar Gyre that started in the mid-2000s. Below 2000 dbar, ISOW increased its contribution in 2014 with respect to 2002–2010, with the increase being consistent with other estimates of ISOW transports along 58–59° N. We also observed an increase in SPMW in the East Greenland Irminger Current in 2014 with respect to 2002–2010, which supports the recent deep convection events in the Irminger Sea. From the assessment of the relative water mass contribution to the Atlantic Meridional Overturning Circulation (AMOC) across the OVIDE line, we conclude that the larger AMOC intensity in 2014 compared to the 2002–2010 mean was related to both the increase in the northward transport of Central Waters in the AMOC upper limb and to the increase in the southward flow of Irminger Basin SPMW and ISOW in the AMOC lower limb.

scholarly journals Interior Water-Mass Variability in the Southern Hemisphere Oceans during the Last Decade

2020 ◽  
Vol 50 (2) ◽  
pp. 361-381 ◽  
Author(s):  
Esther Portela ◽  
Nicolas Kolodziejczyk ◽  
Christophe Maes ◽  
Virginie Thierry
Keyword(s):  
Southern Hemisphere ◽  
Volume Change ◽  
Water Mass ◽  
Lower Layer ◽  
Water Masses ◽  
Ocean Dynamics ◽  
Volume Loss ◽  
South Indian ◽  
Intermediate Waters ◽  
The Antarctic

AbstractUsing an Argo dataset and the ECCOv4 reanalysis, a volume budget was performed to address the main mechanisms driving the volume change of the interior water masses in the Southern Hemisphere oceans between 2006 and 2015. The subduction rates and the isopycnal and diapycnal water-mass transformation were estimated in a density–spiciness (σ–τ) framework. Spiciness, defined as thermohaline variations along isopycnals, was added to the potential density coordinates to discriminate between water masses spreading on isopycnal layers. The main positive volume trends were found to be associated with the Subantarctic Mode Waters (SAMW) in the South Pacific and South Indian Ocean basins, revealing a lightening of the upper waters in the Southern Hemisphere. The SAMW exhibits a two-layer density structure in which subduction and diapycnal transformation from the lower to the upper layers accounted for most of the upper-layer volume gain and lower-layer volume loss, respectively. The Antarctic Intermediate Waters, defined here between the 27.2 and 27.5 kg m−3 isopycnals, showed the strongest negative volume trends. This volume loss can be explained by their negative isopyncal transformation southward of the Antarctic Circumpolar Current into the fresher and colder Antarctic Winter Waters (AAWW) and northward into spicier tropical/subtropical Intermediate Waters. The AAWW is destroyed by obduction back into the mixed layer so that its net volume change remains nearly zero. The proposed mechanisms to explain the transformation within the Intermediate Waters are discussed in the context of Southern Ocean dynamics. The σ–τ decomposition provided new insight on the spatial and temporal water-mass variability and driving mechanisms over the last decade.

Distribution des spectres de taille des particules en suspension dans le fjord du Saguenay

1979 ◽  
Vol 16 (2) ◽  
pp. 240-249 ◽  
Author(s):  
J. P. Chanut ◽  
S. A. Poulet
Keyword(s):  
Particle Size ◽  
Water Mass ◽  
Layer Structure ◽  
Principal Component ◽  
Water Masses ◽  
Size Spectra ◽  
Lawrence Estuary ◽  
Saguenay Fjord ◽  
Bottom Waters ◽  
St Lawrence Estuary

The spatial distribution of particle size spectra shows a two-layer stratification in May but reveals three-layer structure in September, both in the Saguenay fjord and in the adjacent waters of the St. Lawrence estuary, near the sill. In May, the particle size spectra in the surface layer show considerable variability whereas, in the bottom waters, they appear to be relatively homogeneous. In September, the deeper, more homogeneous water mass is less extensive. It is apparently eroded by diffusion and advection during summer months and becomes restricted to intermediate depths towards the head of the fjord. During the same period, a water mass with physical and particulate properties different from the upper layers occupies the bottom of the fjord. Principal component analysis shows that variations in particle size spectra are independent from one layer to another. Water masses with identical physical and particulate properties located in both sides of the sill illustrate the influence of the St. Lawrence estuary on the Saguenay fjord. These water masses, generally located below the sill depth, indicate the existence of powerful advective mechanisms in this region.

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