New Underwater Photosynthesis and Respiration Instrument
What is CISME?
- The name derives from 'Community In Situ MEtabolism', and is pronounced ‘kiss‐me’ to reflect the gentle interaction between the instrument and the coral/substrate.
- A diver‐portable respirometer developed to measure metabolic rates of reef corals in situ under ambient conditions.
- CISME also works with algae and other low‐relief benthic substrates.
- CISME measures changes in oxygen and pH during short incubations in which water flow and light levels are user controlled.
- Respiration (R) and photosynthesis (P) rates are calculated from these concentration changes.
- R and P can be calculated both based on O2 and CO2 fluxes, from which RQs and PQs can be calculated.
- Sample loops provide water samples that can be titrated for total alkalinity to calculate calcification rate.
- The sample loop can also be used to experimentally introduce substances that might affect coral metabolism (e.g. acidified seawater for OA studies).
CISME Instrument Design
Electronics Housing: electronics components are contained in a pressure-resistant acrylic housing (80 m depth) connected by waterproof cables to the incubation flow‐sensor ‘head’.
Incubation Head: housing the sensors, pump, LED light source is attached by the user to the coral/substrate surface with special retractors.
Instrument Operation: CISME is operated with a proprietary Android app on a submersible Android tablet (not included) connected to the CISME by a WiFi cable.
Diver Portability: Instrument and underwater tablet together are ca. 5‐7 lbs negative UW.
- Measures O2 with Presens® optode and pH with Honeywell DuraFet® electrode at 1 sec interval
- Recirculating incubation volumes produced by closed cell foam seal that traps seawater within CISME against low relief surfaces: corals, reef substrates such as turf and coralline algae, settlement plates
- Non‐destructive sampling for massive corals with low rugosity surfaces
- Programmable flow from 350 to 1200 ml min‐1; rpm feedback from pump
- Programmable Light levels (PAR): 0 – 2500 μmol m‐2 s‐1
- Programmable incubation routines (R, P, R+P, P+R, Custom multistep); P vs I curves can be pre‐programmed
- Removable sample loop volume used to collect incubation water subsamples or introduce additives
- Incubation volume: 71 ml with no sample loop; 88 ml with a 16 ml sample loop; 100 ml with flow cup
- Optional sample cup for use with coral fragments, algae, small invertebrates and other detached organisms, and core tube adaptor for use with in situ sediments
- Designed to maximize data collection by divers: short incubations of 5 to 60 minutes duration, depending on organism and desired measurements; calcification takes longer than just respiration and photosynthesis
- High capacity external battery power allows up to 8 hours of use before recharging
- Housing customized to house a Samsung Galaxy S2 8”
CISME was developed by Drs. Alina M. Szmant and Robert F. Whitehead, University of North Carolina Wilmington Center for Marine Science with funding from NOAA OER Grant NA09OAR4320073. They have a set of instruments available for testing by trained and qualified research divers who are willing to collaborate with CISME Instruments by giving feedback. A few “early adopter” units are available for sale.
CISME instruments are sold through Bay Instruments.