{"id":{"repo_id":"cape-town","oai_identifier":"oai:open.uct.ac.za:11427/17079"},"canonical_url":"https://search.dev.ndltd.org/etd/cape-town/oai:open.uct.ac.za:11427/17079","repository":{"repo_id":"cape-town","name":"University of Cape Town","base_url":"https://open.uct.ac.za/oai/request"},"display":{"title":"The effect of chlorine, heat and physical stress on entrained plankton at Koeberg Nuclear Power Station","abstract":"The large volume of seawater used for cooling at Koeberg Nuclear Power Station contains many planktonic organisms which are exposed to heat, chlorine and physical stress during their passage through the system. Phytoplankton biomass, measured as chlorophyll a, was reduced by an average of 55.32% due to entrainment, and productivity was decreased by 38.30% on average, mainly due to chlorination. Zooplankton mortality averaged 22.34% for all species and 30.52% for copepods, the dominant group. The copepod Paracartia africana was used in laboratory experiments designed to simulate entrainment. Latent mortality was monitored up to 60 hours after a 30-minute application of stress factors (physical stress was not simulated), and approximately 75% of the total mortality occurred within the 30-minute period. Male Paracartia experienced higher mortalities than females. Extrapolation of these results predicts an overall entrainment mortality (including latent mortality) of 40% for copepods and 29.04% for total zooplankton, although the latter cannot be substantiated. Plankton entrainment at Koeberg was not considered to be overly detrimental to the marine environment because of the very localised area affected, rapid dispersion of heat and chlorine, rapid regeneration times of phytoplankton and some zooplankton, low abundance of commercially important species and potential recruitment from the surrounding productive Benguela upwelling region.","abstract_html":"The large volume of seawater used for cooling at Koeberg Nuclear Power Station contains many planktonic organisms which are exposed to heat, chlorine and physical stress during their passage through the system. Phytoplankton biomass, measured as chlorophyll a, was reduced by an average of 55.32% due to entrainment, and productivity was decreased by 38.30% on average, mainly due to chlorination. Zooplankton mortality averaged 22.34% for all species and 30.52% for copepods, the dominant group. The copepod Paracartia africana was used in laboratory experiments designed to simulate entrainment. Latent mortality was monitored up to 60 hours after a 30-minute application of stress factors (physical stress was not simulated), and approximately 75% of the total mortality occurred within the 30-minute period. Male Paracartia experienced higher mortalities than females. Extrapolation of these results predicts an overall entrainment mortality (including latent mortality) of 40% for copepods and 29.04% for total zooplankton, although the latter cannot be substantiated. Plankton entrainment at Koeberg was not considered to be overly detrimental to the marine environment because of the very localised area affected, rapid dispersion of heat and chlorine, rapid regeneration times of phytoplankton and some zooplankton, low abundance of commercially important species and potential recruitment from the surrounding productive Benguela upwelling region.","abstract_has_math":false,"creators":["Huggett, Jenny A"],"institution":"Department of Biological Sciences","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Cook, Peter"],"committee_chairs":[],"committee_members":[],"year":1988,"date_issued":"1988","date_published":"1988","updated_at":"2026-07-22T22:22:57Z","subjects":[],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/11427/17079","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Cook, Peter"]},{"key":"dc:creator","label":"Author","values":["Huggett, Jenny A"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2016-02-17T07:15:33Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2016-02-17T07:15:33Z"]},{"key":"dc:date.issued","label":"Date","values":["1988"]},{"key":"dc:publisher.department","label":"Dc Publisher Department","values":["Department of Biological Sciences"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of Cape Town"]},{"key":"dc:type","label":"Dc Type","values":["Master Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["Masters"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["MSc"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["eng"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/11427/17079"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Bibliography: pages 112-138."]},{"key":"dc:description.abstract","label":"Abstract","values":["The large volume of seawater used for cooling at Koeberg Nuclear Power Station contains many planktonic organisms which are exposed to heat, chlorine and physical stress during their passage through the system. Phytoplankton biomass, measured as chlorophyll a, was reduced by an average of 55.32% due to entrainment, and productivity was decreased by 38.30% on average, mainly due to chlorination. Zooplankton mortality averaged 22.34% for all species and 30.52% for copepods, the dominant group. The copepod Paracartia africana was used in laboratory experiments designed to simulate entrainment. Latent mortality was monitored up to 60 hours after a 30-minute application of stress factors (physical stress was not simulated), and approximately 75% of the total mortality occurred within the 30-minute period. Male Paracartia experienced higher mortalities than females. Extrapolation of these results predicts an overall entrainment mortality (including latent mortality) of 40% for copepods and 29.04% for total zooplankton, although the latter cannot be substantiated. Plankton entrainment at Koeberg was not considered to be overly detrimental to the marine environment because of the very localised area affected, rapid dispersion of heat and chlorine, rapid regeneration times of phytoplankton and some zooplankton, low abundance of commercially important species and potential recruitment from the surrounding productive Benguela upwelling region."]},{"key":"dc:title","label":"Title","values":["The effect of chlorine, heat and physical stress on entrained plankton at Koeberg Nuclear Power Station"]}]}],"canonical_facts":{"dc:contributor.advisor":["Cook, Peter"],"dc:creator":["Huggett, Jenny A"],"dc:date.accessioned":["2016-02-17T07:15:33Z"],"dc:date.available":["2016-02-17T07:15:33Z"],"dc:date.issued":["1988"],"dc:description":["Bibliography: pages 112-138."],"dc:description.abstract":["The large volume of seawater used for cooling at Koeberg Nuclear Power Station contains many planktonic organisms which are exposed to heat, chlorine and physical stress during their passage through the system. Phytoplankton biomass, measured as chlorophyll a, was reduced by an average of 55.32% due to entrainment, and productivity was decreased by 38.30% on average, mainly due to chlorination. Zooplankton mortality averaged 22.34% for all species and 30.52% for copepods, the dominant group. The copepod Paracartia africana was used in laboratory experiments designed to simulate entrainment. Latent mortality was monitored up to 60 hours after a 30-minute application of stress factors (physical stress was not simulated), and approximately 75% of the total mortality occurred within the 30-minute period. Male Paracartia experienced higher mortalities than females. Extrapolation of these results predicts an overall entrainment mortality (including latent mortality) of 40% for copepods and 29.04% for total zooplankton, although the latter cannot be substantiated. Plankton entrainment at Koeberg was not considered to be overly detrimental to the marine environment because of the very localised area affected, rapid dispersion of heat and chlorine, rapid regeneration times of phytoplankton and some zooplankton, low abundance of commercially important species and potential recruitment from the surrounding productive Benguela upwelling region."],"dc:identifier.uri":["http://hdl.handle.net/11427/17079"],"dc:language.iso":["eng"],"dc:publisher.department":["Department of Biological Sciences"],"dc:publisher.institution":["University of Cape Town"],"dc:title":["The effect of chlorine, heat and physical stress on entrained plankton at Koeberg Nuclear Power Station"],"dc:type":["Master Thesis"],"dc:type.qualificationlevel":["Masters"],"dc:type.qualificationname":["MSc"]},"updated_at":"2026-07-22T22:22:57Z"}