OTEC Environmental Impact

OTEC

Warm Water Intake:•Entrainment•Impingement

Cold water intake:•Entrainment

Operational Noise

Discharge Plume:•Redistribution of nutrients•Algae blooms•Altered temperature and pH•Where will it settle?

Biota attraction or avoidance

OTEC Environmental Impact

• 1981 EIS+: update to current oceanographic standards

• What data do we need? Stakeholder meeting, June 2010– Oceanography: baseline nutrients, carbon cycle, T, S, O– Plankton, fish larvae: distributions and density– Megafauna habitat use

• What data is already available?

NOAA. 1981. Ocean thermal energy conversion final environmental impact statement.” OME.NOAA. 2010. “OTEC: Assessing potential physical, chemical, and biological impacts and risks.” CRRC. 39pp.

Discharge plume: what data is available?

The Hawaii Ocean Time Series (HOTS)– 1989 – present– Temperature, Salinity, oxygen, pH,

chlorophyll a

Gaps in data:• Nutrients (1989-2001 only)• Alkalinity and DIC at deep depths• Trace metals

Entrainment: Warm Water Pipe

Boehlert and Mundy 1994. Mar Ecol. Prog. Ser. 107:1-13+Seapy. 2008. Mar. Biol. 154(6): 985-995++Poe and Norenburg. 1999. Deep-Sea Res. (1 Oceanogr. Res. Pap.) 46(7): 1201-1220

Entrainment: Cold Water Pipe

West Hawai’i Explorations Academy

Flow rate of 0.8m3/s Compare to pilot plant: 25m3/s

and commercial plant: 500m3/s

Baseline monitoring

• Stakeholder meeting++ – Oceanography : 3 years– Ichthyoplankton: 1 year+– Marine Mammals and turtles: 1 year– Plankton: 2 years

• Taking into account available datasets….

Baseline Monitoring Suggestions

cafethorium.whoi.edu

Discrete-depth sampling for bacteria, copepods, total biomass

1 year:Nutrients, trace metals, and deep water carbon cycle

Consistent monitoring of CWP at NELHA Don’t forget:

Background acousticsFishing/backscatter for nektonMegafaunal habitat use