Effects of temperature on in vitro sediment reworking processes by a gallery biodiffusor, the polychaete Neanthes virens

Abstract

Temperature-induced variations in bioturbation could affect sediment mixing processes in the marine benthic environment. In this study, sediment reworking by Neanthes virens (Sars), a widely distributed polychaete in muddy sand communities of northern temperate latitudes, was studied under different temperature conditions representing winter (1°C), spring and fall (6°C), summer (13°C), and tide pool (18°C) temperatures in the lower St. Lawrence Estuary, Québec, Canada. Sediment reworking was quantified using inert fluorescent particles (luminophores) deposited at the sediment surface. Based on the 1-D luminophore distributions obtained after 5 and 30 d, the use of the specific 'gallery-biodiffusor' model allowed us to quantify both biodiffusion (D b ) and biotransport (V b ) due to the organisms. Our results showed temperature effects on sediment transport. The lowest biotransport and biodiffusion coefficients were measured at 1 and 6°C and did not change with time. The highest biodiffusion occurred at 13°C for both sampling periods. At 18°C, biodiffusion was intermediate while biotransport was maximal. Differences between the 13°C biodiffusive transport and the other temperatures increased with time. Low transport values at 1 and 6°C suggest that a quiescent stage exists for this species at these temperatures, with sediment mixing occurring mostly during burrow construction. On the other hand, sediment mixing resulted from both the burrow construction and maintenance phases at higher temperatures (13 and 18°C).

Influence of temperature on surface sediment disturbance by freshwater fish: a microcosm experiment

“…So far, the only studies dealing with the effect of temperature on sediment disturbance were conducted for marine invertebrates (e.g., Hollertz and Ducheˆne, 2001;Ouellette et al, 2004;Maire et al, 2007). They all reported an increase in sediment reworking with rising temperature.…”

“…Such thermal thresholds in sediment reworking have been reported in White et al (1987) for oligochaetes experiencing cycles of fall and rise temperatures between 4 and 20 xC, and in Berkenbusch and Rowden (1999) who followed the rate of sediment expulsion by a burrowing shrimp over a 12-month period. Nevertheless, most other previous studies that have focused on the relationship between temperature and sediment reworking have been limited to two or three temperature treatments (Ouellette et al, 2004;Maire et al, 2007), probably for practical and technical constraints. Further experimental work conducted in a controlled temperature room where a continuous warming would be simulated would make it possible to precisely measure the fine relationship between temperature and SSD and to identify a potential peak activity in fish sediment disturbance activity.…”

“…For instance, White et al (1987) reported a 90% decline in sediment reworking rate by oligochaetes from the Laurentian Great Lakes when temperature was experimentally lowered from 10 to 4 xC. Ouellette et al (2004) documented a higher sediment transport by a marine polychaete species at warm (13 and 18 xC) than at cold (1 and 6 xC) temperatures. Similar trends were found for the bioturbation activity by a heart urchin (Hollertz and Ducheˆne, 2001) or the reworking rate by a surface deposit-feeding bivalve (Maire et al, 2007).…”

“…Although some studies have assessed the role of temperature in regulating the activity of sediment reworking (e.g., White et al, 1987;Ouellette et al, 2004), these have not yet assessed this for freshwater fish. The studies completed on other biota suggested a strong relationship between sediment reworking and water temperature, both in marine and freshwater systems.…”

Sedimentary phosphorus dynamics and the evolution of bottom‐water hypoxia: A coupled benthic–pelagic model of a coastal system

“…Because faunal metabolism is a function of bottom-water temperature (Ouellette et al 2004), bioturbation is assumed to be a linear function of temperature. Lowest temperatures occur at BY2 in March immediately prior to the spring bloom.…”