Fish Interactions with a Commercial-Scale Tidal Energy Device in the Natural Environment

Viehman, Haley; Zydlewski, Gayle Barbin

doi:10.1007/s12237-014-9767-8

Cited by 81 publications

(88 citation statements)

References 30 publications

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“…We previously observed that fish move more randomly during slack tides [31]. This is further supported by fish direction reported in this study (Fig 5).…”

Section: Discussionsupporting

confidence: 91%

Multi-scale temporal patterns in fish presence in a high-velocity tidal channel

Viehman

Zydlewski

2017

PLoS ONE

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The natural variation of fish presence in high-velocity tidal channels is not well understood. A better understanding of fish use of these areas would aid in predicting fish interactions with marine hydrokinetic (MHK) devices, the effects of which are uncertain but of high concern. To characterize the patterns in fish presence at a tidal energy site in Cobscook Bay, Maine, we examined two years of hydroacoustic data continuously collected at the proposed depth of an MHK turbine with a bottom-mounted, side-looking echosounder. The maximum number of fish counted per hour ranged from hundreds in the early spring to over 1,000 in the fall. Counts varied greatly with tidal and diel cycles in a seasonally changing relationship, likely linked to the seasonally changing fish community of the bay. In the winter and spring, higher hourly counts were generally confined to ebb tides and low slack tides near sunrise and sunset. In summer and fall of each year, the highest fish counts shifted to night and occurred during ebb, low slack, and flood tides. Fish counts were not linked to current speed, and did not decrease as current speed increased, contrary to observations at other tidal power sites. As fish counts may be proportional to the encounter rate of fish with an MHK turbine at the same depth, highly variable counts indicate that the risk to fish is similarly variable. The links between fish presence and environmental cycles at this site will likely be present at other locations with similar environmental forcing, making these observations useful in predicting potential fish interactions at tidal energy sites worldwide.

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“…We previously observed that fish move more randomly during slack tides [31]. This is further supported by fish direction reported in this study (Fig 5).…”

Section: Discussionsupporting

confidence: 91%

Multi-scale temporal patterns in fish presence in a high-velocity tidal channel

Viehman

Zydlewski

2017

PLoS ONE

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“…We are not discussing other hydrokinetic devices. Although instream propeller turbines are not associated with a barrage or causeway and fishes are thought to have greater probability of avoidance (Viehman & Zydlewski, ; Shen et al, ; Bevelhimer et al, ). The probability of turbine encounter in the open ocean depends on numerous conditions such as the number and distribution of turbines, turbine size, probability of behavioral avoidance, benthic or pelagic species relative to turbine position in the water column, year, month and tidal stage (Shen et al, ).…”

Section: Resultsmentioning

confidence: 99%

Long‐term effect of a tidal, hydroelectric propeller turbine on the populations of three anadromous fish species

Dadswell

Spares

McLean

et al. 2018

Journal of Fish Biology

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Tidal hydroelectric power has been proposed as one potential solution for sustainable energy sources. The first tidal turbine in North America began continuous operation in the Annapolis River estuary (44 °45'N; 65° 29'W) in June, 1985. The machine is an axial-flow, hydraulic-lift propeller turbine, a type known to cause fish mortality. Anadromous populations of American shad Alosa sapidissima, striped bass Morone saxatilis and Atlantic sturgeon Acipenser oxyrinchus utilize the Annapolis River for spawning and other life history phases. After power generation commenced obvious turbine mortalities of these fishes began appearing downstream of the turbine. Assessments of the A. sapidissima adult spawning runs during 1981-1982 (pre-operation) and 1989-1996 (operational) indicated significant changes in population characteristics after power generation began. Adult length, mass, age and per cent repeat spawners declined and total instantaneous mortality (Z) increased from 0.30 to 0.55. The pre-turbine spawning runs had older fish with numerous adult cohorts whereas by 12 years after operation began runs consisted of younger fish with fewer adult cohorts. During 1972-1987 numerous studies indicated the Annapolis River had an important angling fishery for M. saxatilis, but detailed annual records kept by a fishing contest during 1983-1987 and an elite angler family during the period 1976-2008 demonstrated a rapid decline in the number of fish >4.0 kg after turbine operation began. Pre-turbine catch by the angling family of fish >4.0 kg accounted for 84.1% of total catch, but declined significantly to 39.6% of total catch from 1986-1999, and to none from 2000-2008. The existence of an A. oxyrinchus stock in the Annapolis River was unknown before turbine operation, but during 1985-2017, 21 mortalities were recovered by chance seaward of the turbine. Mechanical strike and cavitation mortalities consisted of juveniles, mature males and gravid and spent females of ages 10 to 53 years found during June to October, the period when this anadromous species returns to its natal river to spawn. The results of the long-term studies at Annapolis indicate managers should realize substantial risks exist for the fish resources of the world's oceans from deployment of instream propeller turbines.

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“…Similarly, only limited information is available on how these fish species behave at tidal-stream sites. Although comparatively small fish (< 20 cm) have been observed to maintain school cohesion at current speeds up to 2 m s −1 (Viehman & Zydlewski 2015), faster flows and turbulent shear associated with tidal fronts and vortices rising from the seabed may disrupt the ability of fish to control their position, orientation and schooling behaviours. Opportunities for predators may therefore arise from fish being involuntarily displaced or disoriented.…”

Section: Discussionmentioning

confidence: 99%

Riding the tide: use of a moving tidal-stream habitat by harbour porpoises

Benjamins

Dale²,

Geel³

et al. 2016

Mar. Ecol. Prog. Ser.

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Tidal-stream habitats present periodically fast-flowing, turbulent conditions. Evidence suggests that these conditions benefit top predators such as harbour porpoises Phocoena phocoena, presumably allowing them to optimise exploitation of prey resources. However, clear demonstration of this relationship is complicated by the fact that strong tidal flows often occur near-simultaneously across a wide area. The Great Race of the Gulf of Corryvreckan (western Scotland, UK) is a jetting tidal system where high-energy conditions persist across a broad range of tidal phases in a localised, moving patch of water. Porpoises can therefore actively enter or avoid this habitat, facilitating study of their usage of adjacent high-and low-energy environments. The distribution of harbour porpoises was studied using passive acoustic porpoise detectors (C-PODs) deployed on static moorings (~35 d) and on Lagrangian drifters moving freely with the current (up to ~48 h). This dual approach provided complementary perspectives on porpoise presence. C-PODs moored in the path of the Great Race registered a significant increase in detections during the passing of the energetic tidal jet. Encounter durations recorded by drifting C-PODs were longer than those recorded by moored C-PODs, suggesting that porpoises tended to move downstream with the flow rather than remaining stationary relative to the seabed or moving upstream. The energetic, turbulent conditions of the Great Race are clearly attractive to porpoises, and they track its movement with time; however, their structured movements in response to the evolving tidal situation cannot simply be represented as a direct relationship between current speed and porpoise presence.

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Fish Interactions with a Commercial-Scale Tidal Energy Device in the Natural Environment

Cited by 81 publications

References 30 publications

Multi-scale temporal patterns in fish presence in a high-velocity tidal channel

Multi-scale temporal patterns in fish presence in a high-velocity tidal channel

Long‐term effect of a tidal, hydroelectric propeller turbine on the populations of three anadromous fish species

Riding the tide: use of a moving tidal-stream habitat by harbour porpoises

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