West Coast HABs affect: Fish (both wild and pennedMarine BirdsMarine MammalsHumans & InvertebratesHARMFUL ALGAL BLOOMSThe definition of a HAB is not clear-cut, since it is a societal term,not a scientific term, that describes a diverse array of blooms(both macroscopic and macroscopic) that can cause detrimentaleffects to national economies.HARMFUL ALGAL BLOOMSThe definition of a HAB is not clear-cut, since it is a societal term,not a scientific term, that describes a diverse array of blooms(both macroscopic and macroscopic) that can cause detrimentaleffects to national economies, including: Toxic effects on humans and other organisms –generally caused by biotoxinsHARMFUL ALGAL BLOOMSThe definition of a HAB is not clear-cut, since it is a societal term,not a scientific term, that describes a diverse array of blooms(both macroscopic and macroscopic) that can cause detrimentaleffects to national economies, including: Toxic effects on humans and other organisms –generally caused by biotoxins Physical impairment/death of fish/shellfishHARMFUL ALGAL BLOOMSThe definition of a HAB is not clear-cut, since it is a societal term,not a scientific term, that describes a diverse array of blooms(both macroscopic and macroscopic) that can cause detrimentaleffects to national economies, including: Toxic effects on humans and other organisms –generally caused by biotoxins Physical impairment/death of fish/shellfish Nuisance conditions – odors and discolourationaffecting recreation/tourismHARMFUL ALGAL BLOOMSThe definition of a HAB is not clear-cut, since it is a societal term,not a scientific term, that describes a diverse array of blooms(both macroscopic and macroscopic) that can cause detrimentaleffects to national economies, including: Toxic effects on humans and other organisms –generally caused by biotoxins Physical impairment/death of fish/shellfish Nuisance conditions – odors and discolourationaffecting recreation/tourism Overwhelming effects on ecosystemsBlooms of single-celled microorganisms (phytoplankton) thatattain such densities that they discolour the seawater; themost common ‘red tides’ are motile, dinoflagellatesRed Tides Blooms of single-celled microorganisms (phytoplankton) thatattain such densities that they discolour the seawater; themost common ‘red tides’ are motile, dinoflagellates A poor term since they have: Nothing to do with tides (although always coastal), Not necessarily red in colour (can be red/brown/green/orange)Red Tides Blooms of motile dinoflagellates are the most common‘red tides’ Normally dinoflagellates are found in concentrations of~ 100 cells per litre During blooms, concentrations are 1-2 X 106 cells/litre discolouration is size-dependent(ranges from 200-500 cells/L up to 108 cells/L) blooms may be also harmful at low densities due totoxin productionDinoflagellatesRed Tides are not New!• Written reports have suggested ‘red tides’ since biblical times(1,000 BC)• Exodus, Chap. 7, Vs 20-21• “… all the water that were in the river were turned to blood. Andthe fish that were in the river died; and the river stank, and theEgyptians could not drink of the water of the river; and therewas blood throughout all the land of Egypt.”• Describes the first of the 10 great plagues of EgyptMost Red Tides are Harmless! Remember of the ~ 3400-4,100 extant marinephytoplankton species: only 300 species reach densities for waterdiscolouration - ‘red-tides’ (7%) 60-80 species of these 300 spp. are harmful (2%),and only half of these have the capacity to producetoxins (1%)HABs are found world-wide in coastal regionsThree Basic Types of Harmful AlgalBloomsν Indiscriminate Kill of Marine Fauna(Marine Fauna Mass Mortality)ν Selective Fish (Marine Fauna) Killers(usually toxins produced)ν Toxic Vectoring Through Food Chain( i.e., paralytic shellfish poisoning)Indiscriminate Kill of Marine Fauna(Marine Fauna Mass Mortality)This type of HAB is due to the creation ofanoxic conditions:Resulting in the indiscriminate mortality ofmarine fauna, including fish andinvertebrates. Any phytoplankton species could potentiallycause such a HAB in a coastal environmentThe series of events leading to such aHAB: phytoplankton grow and multiply, increase indensity - a “flowering” or bloom eventThe series of events leading to such aHAB: phytoplankton grow and multiply, increase indensity - a “flowering” or bloom event cells become concentrated physically – onshore winds, semi-enclosed bayThe series of events leading to such aHAB: phytoplankton grow and multiply, increase indensity - a “flowering” or bloom event cells become concentrated physically – onshorewinds, semi-enclosed bay nutrients needed for their continued growth areeventually exhaustedThe series of events leading to such aHAB: phytoplankton grow and multiply, increase indensity - a “flowering” or bloom event cells become concentrated physically – onshorewinds, semi-enclosed bay nutrients needed for their continued growth areeventually exhausted phytoplankton cells die, and are decomposed(which requires oxygen) by bacterial respirationThe series of events leading to such aHAB: phytoplankton grow and multiply, increase indensity - a “flowering” or bloom event cells become concentrated physically – onshorewinds, semi-enclosed bay nutrients needed for their continued growth areeventually exhausted phytoplankton cells die, and are decomposed(which requires oxygen) by bacterial respiration waters become low in oxygen or become oxygendepleted (anoxic)The series of events leading to such aHAB: phytoplankton grow and multiply, increase indensity cells become concentrated physically – onshorewinds, semi-enclosed bay nutrients needed for their continued growth areeventually exhausted phytoplankton cells die, and are decomposed(which requires oxygen) by bacterial respiration waters become low in oxygen or become oxygendepleted (anoxic) indiscriminate death of marine faunaFactors contributing to dinoflagellate blooms A seed population (resting cysts or hyphocysts) High surface temperature and lower salinities Winds- Strong offshore winds aid upwelling - advect inorganic nutrients from deeper waters to the