474
N. A. H. El Semary
dinoflagellates are toxin- and endocrine disturbing chemicals-producers with serious
health effects on other organisms and they are the major causal agents for Red-tide
phenomenon. They are major killers of fish through poisoning and blocking of gills.
On the other hand, they are major contributors to the food web as primary producers
the base of food chain. Major contributor to several marine coral communities in
symbiosis with other organisms such as zoothanthalae.
According to [40], the extent of biodiversity within dinophytes is largely underrepresented and new species/genera are being added annually. Areas like Middle
East and Africa are profoundly underexplored and only limited records, if any,
are available. Culture collections to study their characteristics are not available for
most of heterotrophic species simply because their living prey is unknown. Common taxonomic treatment is largely morphology-based. The information from light
and electron microscopy provides the basis for morphological description. Taxonomic criteria: cingulum position and sulcus width, tabulation pattern & hyposome
and episome size, nucleus position & presence of lists. For heterotrophic sp. we
refer to its parts as epi- and hypocone unlike phototrophic sp. we refer to them as
epi- and hypotheca. [41] listed some examples of toxin-producing dinoflagellates
which include Gymnodinium spp., Alexandrium spp. and Pyrodinium spp. that are
responsible for Shellfish Poisoning caused by Saxitoxins (heterocyclic neurotoxic
Guanidine). The symptoms include Tingling and numbness of the perioral area and
extremities, loss of motor control, drowsiness, in severe cases respiratory paralysis.
Also Karenia brevis toxins are responsible for neurotoxic shellfish poisoning caused
by brevetoxins (lipid soluble cyclic polyethers). They cause gastrointestinal symptoms like nausea and diarrhea as well as neurological symptoms. Other genera such
as Dinophysis spp. and Procentrum spp. cause Diarrhetic Shellfish Poisoning caused
by okadaic acid. The symptoms include gastrointestinal symptoms like vomiting and
diarrhea. Nevertheless, okadaic acids are carcinogenic.
6 Overlooked Hazards: Toxic and Harmful Invasive
Species Introduction by Ballast Water and Biofouling
Biofouling means the colonization of aquatic structures/vehicles such as ships
with algae and other organisms. With regard to biofouling microalgae, the
following website (http://www.gisp.org/publications/toolkit/BiofoulingGuidelines.
pdf) reported that they can cling to other fouling species and to aquatic vehicles such
as ships and boats as well as residing in microspaces and pipes. Biofouling not only
causes a negative ecological impact but also negative economic and health impacts.
For example, biofouling can introduce harmful invasive species into national waters.
This has many negative impacts that may include: Outcompeting indigenous species
with regard to space and food; preying upon indigenous species; altering environmental conditions and reducing indigenous biodiversity through causing extinctions
[42].
N. A. H. El Semary
dinoflagellates are toxin- and endocrine disturbing chemicals-producers with serious
health effects on other organisms and they are the major causal agents for Red-tide
phenomenon. They are major killers of fish through poisoning and blocking of gills.
On the other hand, they are major contributors to the food web as primary producers
the base of food chain. Major contributor to several marine coral communities in
symbiosis with other organisms such as zoothanthalae.
According to [40], the extent of biodiversity within dinophytes is largely underrepresented and new species/genera are being added annually. Areas like Middle
East and Africa are profoundly underexplored and only limited records, if any,
are available. Culture collections to study their characteristics are not available for
most of heterotrophic species simply because their living prey is unknown. Common taxonomic treatment is largely morphology-based. The information from light
and electron microscopy provides the basis for morphological description. Taxonomic criteria: cingulum position and sulcus width, tabulation pattern & hyposome
and episome size, nucleus position & presence of lists. For heterotrophic sp. we
refer to its parts as epi- and hypocone unlike phototrophic sp. we refer to them as
epi- and hypotheca. [41] listed some examples of toxin-producing dinoflagellates
which include Gymnodinium spp., Alexandrium spp. and Pyrodinium spp. that are
responsible for Shellfish Poisoning caused by Saxitoxins (heterocyclic neurotoxic
Guanidine). The symptoms include Tingling and numbness of the perioral area and
extremities, loss of motor control, drowsiness, in severe cases respiratory paralysis.
Also Karenia brevis toxins are responsible for neurotoxic shellfish poisoning caused
by brevetoxins (lipid soluble cyclic polyethers). They cause gastrointestinal symptoms like nausea and diarrhea as well as neurological symptoms. Other genera such
as Dinophysis spp. and Procentrum spp. cause Diarrhetic Shellfish Poisoning caused
by okadaic acid. The symptoms include gastrointestinal symptoms like vomiting and
diarrhea. Nevertheless, okadaic acids are carcinogenic.
6 Overlooked Hazards: Toxic and Harmful Invasive
Species Introduction by Ballast Water and Biofouling
Biofouling means the colonization of aquatic structures/vehicles such as ships
with algae and other organisms. With regard to biofouling microalgae, the
following website (http://www.gisp.org/publications/toolkit/BiofoulingGuidelines.
pdf) reported that they can cling to other fouling species and to aquatic vehicles such
as ships and boats as well as residing in microspaces and pipes. Biofouling not only
causes a negative ecological impact but also negative economic and health impacts.
For example, biofouling can introduce harmful invasive species into national waters.
This has many negative impacts that may include: Outcompeting indigenous species
with regard to space and food; preying upon indigenous species; altering environmental conditions and reducing indigenous biodiversity through causing extinctions
[42].