Deep water sponges: ecological importance

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Deep water sponges: ecological
importance and threats to their
functioning
Bannister RJ, Kutti T, Fosså JH
Havforskningsinstittutet
Outline
• Background
– What are sponges?
– Ecological importance?
– How do sponges function?
– Responses to the ecosystem
– Sponges in Norway
• Sponge research at IMR
– Ecology
» Ecological importance
– Basic biology
– Physiological stress to suspended sediments
• The future
What are sponges?
• Sponges (Porifera) are the
least evolutionarily advanced
group of the animal kingdom
– Approx. 16,000 spp.
• 4 different classes
– Distributed globally
•
•
•
•
Tropical coral reefs
Temperate rocky shores
Deep-sea polar habitats
Hydrothermal vents
Importance of sponges
Ecologically
• Functional components of benthic ecosystems (Bell 2008)
• Nutrient recycling and mineralisation of carbon & nitrogen
• Provide food source
• Provide shelter/refuge
• Provide habitat
• Provide structural resilience to reefs
How do they function?
Diverse group of filter feeders
Simplistic body plan
– No true tissues or organs
– System of water canals
– Specialised cells
• Feeding
• Respiration
• Reproduction
• Spicule production
• Chemical defense
How do they function?
Feeding
– Highly efficient filter feeders
• Up to 24 000 L water daily per kg of
tissue
– Diverse nutritional demands
• Phytoplankton
• Picoplanton
• Bacteria and viruses
– Symbiotic community
•
•
•
•
•
DON & DOC
Photosynthesis
Nitrogen fixation
Methanogenesis
Sulphate reduction
microvilli
Choanocyte - the pump & filter
How do they function?
Responses to their ecosystem?
Environmental
– Sediment
• Deposited & suspended
• Organic & inorganic
• Polluted & unpolluted
– Substrate
• Type & slope
– Exposure
• Current velocities
• Wave exposures
– Food availability
– Temperature, salinity & acidification
Biological
– Competition & predation
Photo: IMR
Sponges in Norway
• >300 different sponge
species
– Mass sponge aggregations
• Astrophorida
• Axinellida
• Poecilosclerida
– Geodia sp. sponges most
dominant
• Fjords
• Shelf (Norwegian Sea)
• Shelf (Barents Sea)
• Importance of sponges
to Norwegian
ecosystem?
Photo: IMR
Photo: IMR
Research focus at IMR
Increase basic knowledge on deep water sponges
• Ecology
– Distribution and abundance?
• Biology and Physiology
– How do deep water sponges function?
• Feeding
• Pumping
• Respiration
• Responses to anthropogenic changes
– How do sponges cope with suspended sediment
• Mining & oil drilling
• Trawling
• Aquaculture
Træna Deep cold-water coral MPA
Træna Deep cold-water coral MPA
14 towed underwater video transects á 2 km
split into 6 sub-transects
3 of the 6 sub-transects selected
still photos (á 9 m2) taken every 30 s
large-sized sponges identified (and measured)
3.0
Træna Deep cold-water coral MPA
Oceanapia
Asconema type
Aplysilla
G macandrewii
Isops Mycale
Stryphnus
G. barretti
3 different types of sponge
communities were identified
Western side of
depression dominated by
G. barretti, G. atlantica &
G macandrewii
G. atlantica
Mean biomass 2.4 kg m-2
Phakellia
Stelletta
-1.5
Antho
-1.0
3.0
Photo: IMR
3.0
Træna Deep cold-water coral MPA
Oceanapia
Asconema type
Aplysilla
G macandrewii
Isops Mycale
Stryphnus
G. barretti
G. atlantica
Phakellia
3 different types of sponge
communities were identified
The eastern side of the
depression dominated
by fan-shaped Phakellia sp.
sponges and further
characterized by Oceanapia
and Mycale sponges.
Stelletta
-1.5
Antho
-1.0
3.0
Photo: IMR
3.0
Træna Deep cold-water coral MPA
Oceanapia
Asconema type
Aplysilla
G macandrewii
Isops Mycale
Stryphnus
G. barretti
G. atlantica
Phakellia
Stelletta
-1.5
Antho
-1.0
3.0
3 different types of sponge
communities were identified
On both sides of the
depression in areas with
a high density of
cold water corals the
community was
characterized by Geodia spp.
Mycale & Oceanapia spp.
Træna Deep cold-water coral MPA
In the Træna Deep we found a mean of 1 sponge m-2
All area can be characterized as
sponge ground
Massive biomass – what´s the ecological
function?
Biology & Physiology
• 3D reconstruction of the canal system of G.barretti
– Measure the canal and feeding chamber dimensions
– Frictional losses with water flow within a sponge
– Establish model for pumping activity
• Measuring the pumping activity of G.barretti
– Pumping speed (cm s-1)
–Up to 13 cm s-1
– Pumping volume (L)
– Up to 1000 L kg tissue d-1
– Behaviour
–Constant pumping activity
Biology & Physiology
Feeding
chambers
Canal system
Bacteria
Feeding cells
Biology & Physiology
• Feeding biology
– What do cold deep-water sponges feed on?
–Bacteria
Microvilli
Flaggella
–TOC & DOC
Gasket
–Nutrients
–NO2
–NO3
–NH4+
–Si
–PO4
Sediment interactions on deepwater sponges
• How does suspended sediments affect deep-water
sponges?
•Oil drilling operations (NRC)
•Mine dumping
•Aquaculture effluent
Particle size, shape,
conc, and composition
Sediment interactions on deepwater sponges
• How do suspended sediments affect deep-water
sponges?
•Population level
•Distribution and abundance
•Individual level
•Physiology, energetics, reproduction
•Cellular level
•Mucus production, cell death, cell viability, DNA damage
•Molecular level
•Gene expression and metabolomics
Sediment stress on deep-water
sponges
• Exposure experiments
• 12 hr exposure experiments (0, 10, 50, 100 mg/L)
• Natural sediment, bentonite & barite
• Physiological changes
• Cellular and molecular responses
• 14 day exposure experiments (10 and 30 mg/L)
• Chronic (constant exposure)
• Cyclic (12h on / 12h off)
Sediment stress of deep-water
sponges
Sediment stress of deep-water
sponges
Microvilli
Conclusions/Questions
• Ecologically important
– Dominate the benthic shelf system (high biomass)
– Benthic pelagic coupling
• Filtering particulate/dissolved carbon and nitrogen
• Converting this to waste by-products for other organisms
• Rapid pumping response to suspended sediment
loads
– Concentration and particle type dependant
• Acute and long term exposures to barite cause
cellular damage in sponges
Conclusions/Questions
• Lysosomal membrane stability is a useful tool for
monitoring effects of anthropogenic stressors in
sponges
• What is the energetic cost for sponges living under
suboptimal conditions?
– Reproduction?
– Growth?
– Population structure?
• What impact will a loss of sponge biomass on the
shelf mean for the functioning of the ecosystem?
Sponge research team
• Sponge team at IMR
–
–
–
–
Raymond Bannister
Tina Kutti
Jan Helge Fosså
Cathinka Krogness
• SINTEF
• Canada
• Australia
• Denmark
• Netherlands
Acknowledgements
• Research council of Norway
– RESPONSE and SEDEXSPONGE project
• Technical team at IMR
• Crew onboard RV Håkon Mosby
• Statoil - supply of drilling muds
Continental shelf research
Vol. 69, 21-30 (2013)
Aquatic Biology
Vol. 19, 65-73 (2013)
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