Accumulation of domoic acid by the sea scallop (Placopecten magellanicus) fed cultured cells of toxic Pseudo-nitzschia multiseries

1997 ◽  
Vol 54 (4) ◽  
pp. 907-913 ◽  
Author(s):  
D J Douglas ◽  
E R Kenchington ◽  
C J Bird ◽  
R Pocklington ◽  
B Bradford ◽  
...  

Sea scallops (Placopecten magellanicus) were fed Pseudo-nitzschia multiseries (formerly P. pungens f. multiseries, Nitzschia pungens f. multiseries) cells of high domoic acid (DA) content (4.0-6.7 pg DA cdot cell-1) for 22 days, followed by 14 days of feeding with nontoxic microalgae. DA was incorporated within 24 h by the scallops, with increased uptake after 6 days, and was concentrated in tissues in the following order: digestive gland >> remaining soft tissue >> adductor muscle. A maximum DA concentration of 3108 mu g cdot g-1 was recorded in the digestive gland, approximately 150 times the regulatory limit (20 mu g DA cdot g-1) and among the highest levels observed in bivalve molluscs; however, only trace amounts, 0.7-1.5 mu g cdot g-1, were found concomitantly in the adductor muscle. At the end of the exposure period, 50.9% of the DA that had been supplied to the scallops had been incorporated into the tissues. Concentrations in the digestive gland 14 days after termination of the toxic diet remained high, 752 mu g DA cdot g-1. Throughout the experiment, there was no sign of illness or mortality attributable to high DA loading, although the destructive sampling of animals did not allow us to assess the effects of the toxin in the longer term.

1987 ◽  
Vol 44 (1) ◽  
pp. 91-98 ◽  
Author(s):  
J. F. Uthe ◽  
C. L. Chou

Over 90% of the total cadmium in the soft tissues of sea scallops (Placopecten magellanicus) was in the digestive gland with less than 1% in the adductor muscle. The amount of cadmium in the digestive gland was significantly related to shell height. Shell height was superior to age as an independent (predictor) variable due to difficulties in ageing scallops. Based on these relationships, scallops of approximately 100 mm shell height were selected to study interregional differences. Neither cadmium concentration nor burden could be used to identify contaminated areas. The ratio of digestive gland cadmium to that in the adductor muscle was lowest for scallops from Chaleur Bay, which had received substantial anthropogenic cadmium input, and for scallops that had been starved for approximately 14 mo. We suggest that the high tissue cadmium levels in scallops from Georges Bank and Browns Bank are not due to contamination from anthropogenic or natural sources but rather reflect feeding and the nutritional inadequacy of the diets. Conversely, the high levels of cadmium input to Chaleur Bay were not reflected in high tissue concentrations or burdens in scallops.


1983 ◽  
Vol 40 (3) ◽  
pp. 313-318 ◽  
Author(s):  
G. S. Jamieson ◽  
R. A. Chandler

Levels of Gonyaulax excavata toxin in sea scallop (Placopecten magellanicus) tissues were monitored in eastern Canada on a monthly basis between 1977 and 1981. All tissues but the adductor muscle were found to be highly toxic in Bay of Fundy scallops, with negligible toxicity observed in scallops from Georges Bank, the outer Scotian Shelf, and Northumberland Strait scallops. Level of Bay of Fundy toxicity was much higher than previously observed (maximum digestive gland toxicity: 150 000 μg/100 g in March 1978), and recent average monthly toxicity for Bay of Fundy scallop roe ranged from 184 to 286 μg/100 g. Considerable fluctuation in toxicity can occur between adjacent months, and peak toxicities in sea scallops occur during fail and winter months. Scallop roe fisheries should be permitted to be established for scallops fished from the northern part of Georges Bank and Northumberland Strait. However, a closed zone for scallop roe should be established in the Bay of Fundy and adjacent Scotian Shelf.Key words: scallop, PSP, Gonyaulax, Placopecten, mollusk


1978 ◽  
Vol 7 (2) ◽  
pp. 111-118
Author(s):  
David A. Storey ◽  
Cleve E. Willis

The Atlantic sea scallop (Placopecten magellanicus) is harvested in the waters off the coast of the northeastern United States and Canada by vessels from both countries. The Atlantic sea scallop fishery has been an important fishery in the Northeastern U.S. in recent decades. This is particularly true for New England where, during the quarter-century ending in 1976, over 10 percent of the value of all fish and shellfish landed was attributable to the harvest of sea scallops.


2006 ◽  
Vol 63 (5) ◽  
pp. 811-821 ◽  
Author(s):  
Bradley P. Harris ◽  
Kevin D.E. Stokesbury

Abstract Shell growth of sea scallops in two commercially productive regions of the Great South Channel (GSC) (41°4′N 69°16′W) was studied using tag–recapture experiments. Commercial fishers captured and returned 9.7% of the 11 704 sea scallops tagged in the southern GSC study area, and 7.9% of the 18 274 sea scallops tagged in the northern GSC study area. Scallop density and shell height distribution were sampled with underwater video in the two study areas. In the southern GSC tagged scallops grew faster, reached larger asymptotic size, and had higher growth performance (Φ′) than in the northern GSC study area. Mean sea scallop density in the southern GSC was 0.117 scallops m−2 (s.e. = 0.01), and 2.601 scallops m−2 (s.e. = 0.28) in the northern GSC. Environmental factors, fishing pressure, and sea scallop density all influence shell growth on a fine geographic scale (1–100 km2) and should be considered in area-specific management strategies, such as that currently used in the USA sea scallop fishery.


1998 ◽  
Vol 44 (5) ◽  
pp. 456-464 ◽  
Author(s):  
James E Stewart ◽  
L J Marks ◽  
M W Gilgan ◽  
E Pfeiffer ◽  
B M Zwicker

The neurotoxin domoic acid is produced in quantity by the diatom Pseudo-nitzschia multiseries and is released to the environment directly and indirectly via food chains. Presumably there is a mechanism for the biodegradation and disposal of domoic acid and as bacteria are logical candidates for such an activity, a search for bacteria competent to carry out biodegradation of domoic acid was initiated. Extensive trials with a wide variety of bacteria isolated mainly from muds and waters taken from the marine environment showed that the ability to grow on or degrade domoic acid was rare; in fact, domoic acid was inhibitory to resting cells or growing cultures of most of these bacteria. In contrast, using enrichment techniques, it was possible to isolate from molluscan species that eliminate domoic acid readily, i.e., blue mussels (Mytilus edulis) and soft-shell clams (Mya arenaria), bacteria that exhibited growth with and biodegradation of domoic acid when supplemented with low concentrations of growth factors. The species that retain domoic acid for lengthy periods, such as sea scallops (Placopecten magellanicus) and red mussels(Modiolus modiolus), only occasionally yielded bacteria with this capability. The differences may be a result of the mechanisms used by the different shellfish in dealing with domoic acid, i.e., freely available in the blue mussels and soft shell clams but likely sequestered in the digestive glands of sea scallops and red mussels and thus, largely unavailable for bacterial utilization. The results show that Mytilus edulis and Mya arenaria, almost uniquely, are prime and reliable sources of domoic acid utilizing bacteria. These findings suggest a strong possibility that autochthonous bacteria may be significant factors in the elimination of the neurotoxin in these two species of shellfish.Key words: bacteria, neurotoxin, domoic acid, elimination, bivalve molluscs.


1993 ◽  
Vol 50 (9) ◽  
pp. 1857-1869 ◽  
Author(s):  
Jean Côté ◽  
John H. Himmelman ◽  
Michel Claereboudt ◽  
John C. Bonardelli

We examined the influence of depth and stocking density on the growth and survival of juvenile sea scallops (Placopecten magellanicus) in suspended culture at Gascons, Baie des Chaleurs. An increase in density greatly reduced the growth of the shell, adductor muscle, and other tissues, possibly because of lower food availability and diminished space. Growth was also influenced by depth and was greater at 9 m than at 21 m. However, the effect of depth was largely masked by the effect of stocking density and fouling of pearl nets. The pattern of seasonal variations in growth varied with the parameter used to quantify growth, and the changes were correlated with temperature and with chlorophyll a in one size fraction (0.7–5 μm). Survival was high at all depths and densities studied. Maximum growth was obtained at a density of 50 scallops∙net−1. However, the growth was only slightly reduced at 100 scallops∙net−1 and thus, this would be an ideal stocking density for growing scallops commercially if the objective is ear-hanging or bottom-seeding after 1 yr of suspended culture.


1970 ◽  
Vol 27 (3) ◽  
pp. 604-606 ◽  
Author(s):  
Doris Fraser Hiltz

Trigonelline, associated with its isomer homarine, has been found in amounts ranging from 0.7 to 1.3 μmoles/g in scallop adductor muscle. Separation of the two betaines was achieved by column chromatography on a cation-exchange resin, using a linear gradient of 2 N HCl into H2O. Identification of trigonelline was based on spectral properties and on behavior in thin-layer, paper, and column chromatography.


Sign in / Sign up

Export Citation Format

Share Document