The Development of Vertical Migration Patterns in the Sediments of Estuaries as a Strategy for Algae to Resist Drift with Tidal Currents

1985 ◽  
Vol 70 (1) ◽  
pp. 151-164 ◽  
Author(s):  
Charles W. Heckman
Keyword(s):  
Vertical Migration ◽  
Tidal Currents ◽  
Migration Patterns

scholarly journals ADCP observations of migration patterns of zooplankton in the Cretan Sea

2018 ◽  
Author(s):  
Emmanuel Potiris ◽  
Constantin Frangoulis ◽  
Alkiviadis Kalampokis ◽  
Manolis Ntoumas ◽  
Manos Pettas ◽  
...  
Keyword(s):  
Vertical Migration ◽  
Eastern Mediterranean ◽  
Vertical Motion ◽  
Lunar Cycle ◽  
Migration Patterns ◽  
Intimate Link ◽  
Seasonal Circulation ◽  
Continuous Presence ◽  
Adcp Observations ◽  
Cretan Sea

Abstract. The lack of knowledge of the mesopelagic layer inhabitants, especially of those performing strong vertical migration, is an acknowledged challenge as its incomplete representation leads to the exclusion of an active carbon and nutrient pathway from the surface to the deeper layers and reversely. The vertical migration of mesopelagic inhabitants (macro-planktonic and micro-nektonic) was observed by acoustical means in the epi- and mesopelagic layer of the open oligotrophic Cretan Sea (Eastern Mediterranean) for almost 2.5 years at the site of an operational fixed-point observatory located at 1500 m depth. The observed organisms were categorized in four groups according to their migration patterns. The variability of the migration patterns was inspected in relation to the physical and biological environmental conditions of the study area. The stratification of the water column does not act as a barrier for the vertical motion of the strongest migrants, moving up to 400 m every day. Instead, changes of light intensity (lunar cycle, daylight duration, cloudiness) and the presence of prey and predators seem to explain the observed daily, monthly and seasonal variability. The continuous presence of these organisms, yet capable of vertical motion and despite the profound seasonal circulation variability at the site of the observatory, implies their presence in the broader study area. The fundamental implications of the above for biogeochemical processing in oligotrophic seas due to the intimate link of the C and nutrient cycles, are discussed.

Community Structure and Biomass of Euphausiids in the Bay of Fundy

1982 ◽  
Vol 39 (2) ◽  
pp. 326-334 ◽  
Author(s):  
D. W. Kulka ◽  
S. Corey ◽  
T. D. Iles
Keyword(s):  
Life History ◽  
Community Structure ◽  
Vertical Migration ◽  
High Intensity ◽  
Sampling Scheme ◽  
Bay Of Fundy ◽  
Migration Patterns ◽  
Life History Stages ◽  
Diurnal Vertical Migration ◽  
Meganyctiphanes Norvegica

Seven species of euphausiids were found in the Bay of Fundy: Meganyctiphanes norvegica, Thysanoessa inermis, T. longicaudata, T. raschii, T. gregaria, Euphausia krohnii, and Nematoscelis megalops (listed in descending order of abundance). A high-intensity sampling scheme during November and March facilitated detailed distributional studies which revealed that M. norvegica, T. inermis, and T. longicaudata each had a specific stationary center of abundance in the study area, and each species performed a different pattern of diurnal vertical migration. Meganyctiphanes norvegica formed 90% (constituting 70 kt) of the euphausiids. The last four species were occasional immigrants from areas south of the Bay of Fundy. From the relationships between life history stages, vertical migration patterns, distribution, and currents in the Fundy Region, we suggest that these euphausiid species form stocks.Key words: euphausiids, Meganyctiphanes norvegica, Thysanoessa inermis, Thysanoessa longicaudata, biomass, community structure, stock, Bay of Fundy

scholarly journals Vertical distribution of Baltic sprat larvae: changes in patterns of diel migration?

2007 ◽  
Vol 64 (5) ◽  
pp. 956-962 ◽  
Author(s):  
Rüdiger Voss ◽  
Jörn O. Schmidt ◽  
Dietrich Schnack
Keyword(s):  
Vertical Distribution ◽  
Surface Waters ◽  
Vertical Migration ◽  
Diel Vertical Migration ◽  
Behavioural Change ◽  
Migration Patterns ◽  
Near Surface ◽  
Diel Migration ◽  
The Baltic ◽  
Comparison Of The Results

Abstract Voss, R., Schmidt, J. O., and Schnack, D. 2007. Vertical distribution of Baltic sprat larvae: changes in patterns of diel migration? – ICES Journal of Marine Science, 64: 956–962. Ontogenetic and diurnal vertical migration patterns of Baltic sprat larvae were investigated for the periods 1989–1990 and 1998–2002. Comparison of the results led to the hypothesis that the diel vertical migration behaviour of sprat larvae >10 mm has changed. In 1989 and 1990, sprat larvae migrated to the surface at night, whereas they stayed 30–50 m deep by day. From 1998 to 2002, sprat larvae showed no signs of diel vertical migration, remaining in warmer, near-surface water by day and night. This behavioural change coincided with a more general change in the Baltic ecosystem, i.e. an increase in near-surface temperature and a general increase in abundance of the major prey organism (Acartia spp.) of Baltic sprat larvae, with more pronounced aggregation in surface waters.

scholarly journals Diel vertical migration patterns of three zooplankton populations in a Chilean lake

2004 ◽  
Vol 77 (1) ◽  
Author(s):  
RODRIGO RAMOS-JILIBERTO ◽  
JOSÉ L. CARVAJAL ◽  
MAURICIO CARTER ◽  
LUIS R. ZÚÑIGA
Keyword(s):  
Vertical Migration ◽  
Diel Vertical Migration ◽  
Migration Patterns

Vertical Migration in Daphnia galeata mendotae (Brooks): Demographic Responses to Changes in Planktivore Abundance

1990 ◽  
Vol 47 (2) ◽  
pp. 395-400 ◽  
Author(s):  
D. G. Stirling ◽  
D. J. McQueen ◽  
M. R. S. Johannes
Keyword(s):  
Residence Time ◽  
Vertical Migration ◽  
Daphnia Galeata ◽  
Population Densities ◽  
Data Set ◽  
Migration Patterns ◽  
Order Of Magnitude ◽  
Daphnia Galeata Mendotae ◽  
Demographic Responses

We tested the hypothesis that changes in vertical migration patterns in Daphnia galeata mendotae were correlated with changes in planktivore numbers. A 4-yr data set from Lake St. George showed that during 1982, when planktivores numbered approximately 2500∙ha−1, adult D. galeata mendotae were found in the epilimnion at both midday and midnight. During 1984 and 1985, when planktivores were almost an order of magnitude more abundant, adult D. galeata mendotae were detected in the epilimnion only at night, and the amplitude of migration increased by a factor of two. Changes in diel population densities were associated with these interannual differences in vertical migration patterns. These results suggest that between-year differences in vertical migration patterns were strongly associated with changes in planktivore density which may have influenced the selective value of increased hypolimnetic residence time.

scholarly journals Ontogenic changes in diel vertical migration patterns compared with known allometric changes in three mesopelagic squid species suggest an expanded definition of a paralarva

2010 ◽  
Vol 67 (7) ◽  
pp. 1436-1443 ◽  
Author(s):  
Elizabeth K. Shea ◽  
Michael Vecchione
Keyword(s):  
Vertical Migration ◽  
Diel Vertical Migration ◽  
Prey Capture ◽  
Morphological Changes ◽  
Migration Patterns ◽  
Squid Species ◽  
Visual Markers ◽  
Definition Of ◽  
Species Specific ◽  
First Time

Abstract Shea, E. K., and Vecchione, M. 2010. Ontogenic changes in diel vertical migration patterns compared with known allometric changes in three mesopelagic squid species suggest an expanded definition of a paralarva. – ICES Journal of Marine Science, 67: 1436–1443. Planktonic and newly hatched cephalopods are routinely called paralarvae. Currently, the onset of diel vertical migration (DVM) marks the end of the paralarval phase, although changes in ontogenic growth trajectories may also be used. Patterns of DVM are reported for the first time for three poorly understood mesopelagic squid species. Discrete-depth samples taken during the Amsterdam Mid North Atlantic Plankton Expeditions (AMNAPE) of 1980–1983 are used to examine the timing of ecological and morphological changes in Chtenopteryx sicula, Mastigoteuthis magna, and Brachioteuthis sp. 3. DVM patterns are species-specific, and ontogenic changes in DVM coincide with allometric changes in the arm, fin, and funnel characters of C. sicula at 7 mm mantle length. Mastigoteuthis magna is not concentrated in the upper 250 m of the water column during the day, and no clear DVM pattern is found in Brachioteuthis sp. 3, meaning that the endpoint of the paralarval phase cannot be defined ecologically in these species. Other ecological transformations, e.g. changes in prey-capture ability, are therefore explored as alternatives to DVM. The pad-shaped club and long neck are proposed as visual markers of the end of the paralarval phase of C. sicula and Brachioteuthis sp. 3, respectively.

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