| dc.contributor.author | Emerson, Craig William. | en_US |
| dc.date.accessioned | 2014-10-21T12:34:34Z | |
| dc.date.available | 1990 | |
| dc.date.issued | 1990 | en_US |
| dc.identifier.other | AAINN64408 | en_US |
| dc.identifier.uri | http://hdl.handle.net/10222/55176 | |
| dc.description | A series of field and laboratory studies was conducted to determine whether changes in recruitment and production of coastal benthic populations could be attributed to local variations in bedload sediment transport. An empirical model provided the first evidence of bedload-benthos interaction; it was hypothesized that sediment transport was responsible for the negative correlation between sea-surface wind stress and benthic secondary production (BSP) in a multivariate model explaining $\sim$90% of the annual variation in BSP. | en_US |
| dc.description | This hypothesis was tested after developing and calibrating a cylindrical sub-surface bedload trap for use in shallow water. From trap deployments on intertidal sandflats at Eastern Passage, N.S., it was determined that recruitment to a population of soft-shell clams (Mya arenaria), was controlled largely by the passive transport of juveniles (1+ cohort) during bedload transport (max. $>$ 2600 clams$\cdot$m$\sp{-1}$d$\sp{-1}).$ A relatively short period between spat settlement and the onset of fall storms likely contributed to the complete removal of the 0+ cohort from the high-energy sandflat. | en_US |
| dc.description | Additional evidence linking bedload transport to benthic production was revealed in laboratory experiments which tested the effects of sediment disturbance and water flow on Mya arenaria tissue growth. After 10 months, maximum growth (60% increase in dry wt.) was observed in clams exposed to daily disturbance of the top centimeter of sediment; no level of disturbance resulted in growth rates lower than those of undisturbed clams in minimal flow (U = 0.4 cm$\cdot$s$\sp{-1}$; 10% wt. increase). An increased sestonic food supply was responsible for the positive influence of flow but the benefits of sediment disturbance could not be identified. | en_US |
| dc.description | In related experiments, most clams (1-7 cm shell length) could survive a 50-cm sand burial, but died under 25 cm of mud. The inability to re-establish normal living depths after exposure during sediment erosion may increase the susceptibility of clams living in mud to further erosion and erosion and epibenthic predation. Thus, results from theoretical, field and laboratory investigations supported the concept of a physical regulation of coastal benthic energy flow. | en_US |
| dc.description | Thesis (Ph.D.)--Dalhousie University (Canada), 1990. | en_US |
| dc.language | eng | en_US |
| dc.publisher | Dalhousie University | en_US |
| dc.publisher | | en_US |
| dc.subject | Biology, Ecology. | en_US |
| dc.subject | Biology, Oceanography. | en_US |
| dc.title | The effects of bedload sediment transport on benthic recruitment and production with emphasis on the soft-shell clam Mya arenaria L. | en_US |
| dc.type | text | en_US |
| dc.contributor.degree | Ph.D. | en_US |
