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No information can be reproduced without express written permission Is there an ideal method?
Eric Borneman University of Houston Department of Biology and Biochemistry
The Real Thing – What is a Coral Reef? Characteristics:
1. Highly oligotrophic waters 2. High irradiance 3. Warm temperature 4. Very high species diversity 5. Habitat specialization/commensal and symbiotic relations 6. Adjacent community interaction 7. High rates of productivity 8. High rates of calcification 9. Dominated by turf and crustose algae, highly grazed 10. Variable percentage of coral coverage Coral Reefs = Deserts + Rainforests
Organisms are specifically adapted to take advantage of low nutrient availability and high competition
Individually, they would all take more food
Together, if all had more food, the system would shift or collapse Environmental Averages and Extremes for Reef Sites (after Kleypas et al. 1999)
Variable Minimum Maximum Average SD
Temperature (oC) Average 21.0 29.5 27.6 1.1 Minimum 16.0 28.2 24.8 1.8 Maximum 24.7 34.4 30.2 0.6
Salinity (PSU) Minimum 23.3 40.0 34.3 1.2 Maximum 31.2 41.8 35.3 0.9
Nutrients (µmol L-1)
NO3 0.00 3.34 0.25 0.28 PO4 0.00 0.54 0.13 0.08 Physico-chemical Environmental and Potentially Limiting Variables (after Kleypas, et al., 1999)
Variable Reef Limits Time scale
Temperature (oC) 18 annual minima Salinity (PSU) 25-42 continuous Light (µE m-2 s-1) 30-40% SSI (300-500PAR) limits reefs 10% SSI (100-180PAR) limits corals Nutrients (µmol l-1)
NO3 0.5-3.0 PO4 0.1 - 2.0 Mangrove development
While mangroves are often associated with coral reefs, they are extensive terrestrial and coastal elements most often influencing terrestrial runoff to reefs. This mangrove is several kilometers inland from the coast, and another several kilometers from any coral reef development at all. Mangrove habitat
Seagrass Meadows
Coral Reef Differences
A healthy Indo-Pacific coral reef Note windward and leeward sides and the slope development on each. Lagoons
Coastal and Fringing Reefs
Offshore Reefs and Atolls:
Acropora nobilis and A. pulchra Hydroids and Acropora palifera
Many corals may be exposed at low tides
Deepwater Sites
Trachyphyllia geoffroyi
A History of Reefkeeping Major Breakthroughs Water Quality Summary of Berlin and Berlin Hybrid Systems
Note: because of the number of tanks, the time period Variable over which they were kept, improper record keeping over time, and variables that change over time, including variances between o Temperature ( F) systems, makes these water quality data only grossly accurate - mean 80 max/min 86/74 Salinity (ppt) Alkalinity (meq/l) mean 34 4.2 max/min 35/32 2.4/5.3 pH Ca++ mean 8.4 450 max/min 8.6/8.2 520/400 PO4 (ppm) NO2+NO3 (ppm) mean .20-.27 4-10 max/min .40-.80/<.05-.15 8-20/<2 - 6 note: nutrient levels are split. First number is for Berlin Hybrid (with sand), second for Berlin (no sand) Schematic of “typical” Berlin-style Aquarium set-up (Delbeek, Sprung 1994) 500 l Hybrid Berlin System, in operation 5 years (1996)
10 cm sand bed, with plenum 500 l Hybrid Berlin System, in operation 5 years (1996)
10 cm sand bed, with plenum 500 l Hybrid Berlin System, in operation 7 years (1998)
12 cm coarse sand bed, no plenum 500 l Hybrid Berlin System, in operation 9 years (2000)
12 cm coarse sand bed, no plenum Algae Turf Scrubbers and the Dynamic Aquaria Paradigm
Principles: Many species of turf algae, grown on screens and lit in a separate area, are used for nutrient uptake and water quality control Dump buckets housing the algae screens provide non- traumatic natural water flow Deep oolitic aragonite sand beds are integral to the system set-up and provide buffering, trace elements, calcium, denitrification and habitat for flora and fauna Refugia are used as areas free of predation to culture plankton and plankton-like organisms Reverse daylight is used on the screens to maintain pH levels at night and stabilize and keep oxygen at saturation by keeping photosynthesis rates high compared to respiration Biodiversity is stressed in a balanced livestock population Live rock, strong lighting, and nutrient export by algae screen harvest are the basic tenets. Heavy feeding is possible because of the rapid uptake of N and P by algae, accumulation by harvestable biomass, and uptake in the form of ammonia before nitrate is even produced No protein skimming, additives, water changes, or supplemental pumps are required Number of ATS systems maintained: 4 Longest established: 3.5 years Schematic drawing of Smithsonian Caribbean microcosm (Adey, Loveland 1998)
Scrubber lagoon Schematic Drawing of Smithsonian Caribbean Microcosm (Adey, Loveland 1998) Irradiance of Smithsonian Caribbean microcosm (Adey, Loveland 1998) Display Tank, 480 l ATS system, Inland Aquatics (1995)
Refugium
Deep sand bed (no plenum) 160 l ATS aquarium (1998)
Note growth of Sinularia in 3 months Halymenia in refugium 2008 2008 The Jaubert Microcean Ecosystem and Variations
Principles - Water filtration accomplished by the flora and fauna in a thick sediment layer sandwiched between the water column and a confined bottom water layer (plenum)
- High O2 in the water column and low O2 in the plenum create an O2 gradient in the sand bed that provides for stratification of aerobic and denitrifying bacterial populations - Fauna in the “living”sand bed enhances the microbial breakdown process by mimicking natural processes of uptake, assimilation, and breakdown - The sand bed acts as a buffer, calcium source, and sink for various compounds - Sand beds are deep and mechanically separated in layers by screen to prevent burrowers from disturbing stratified and productive deep microbial communities. - Careful attention is given to establishment of pioneer and successional communities prior to predator introduction - diversity and accuracy is stressed. - Live rock, strong water flow, and strong lighting are used and introduces the concept of “live sand” - Protein skimming or other filters are not used ordinarily, and water element additions only if required by individual systems. Water changes are not done unless required.
Number of Jaubert style aquariums maintained: 24 Longest established: 6.5 years Schematic drawing of Jaubert Microcean Ecosystem (Jaubert 1989)
Reference: Jaubert, Jean. 1989. An integrated nitrifying-denitrifying biological system capable of purifying sea water in a closed circuit aquarium. Deuxiéme Congrés international d’Aquariologie (1988) Monaco. Bulletin de l’Institute Océanographique, Monaco, no spécial 5: 101-106. Live rock in a 160 l Jaubert aquarium, no additions (1994)
Protopalythoa sp. Montipora sp. Porites sp. Zoanthus sp.
hydroids 160 l Jaubert aquarium, established four years (1996)
strong water motion
Montipora digitata eventually formed a “microatoll”
Hydnophora rigida
Xenia sp.
Favites sp
Sea “biscuit”
Acanthastrea sp.
Parazoanthus sp. Final Variations - Improvements Over Time
Linked habitats embody principles of all natural methodologies - Live rock, live sand, strong water motion and strong lighting are basic tenets - Refugium is incorporated - Deep denitrifying and functional sand beds are utilized - Reverse daylight principles and algae or plants (seagrasses) are utilized - No protein skimming or other filtration used to maximize the integrity of the water column - No water changes are done - Strong emphasis on producing or the input of live zooplankton and phytoplankton
Differences: - No algae screens used - A surge device replaces most traumatic pumps - No plenum is used - No trace elements or other additions used. - A calcium reactor or calcium/carbon source is utilized (kalkwasser, bicarbonate, etc.) - Carbon is used to manage secondary metabolites produced by huge diversity of organisms Schematic of Multi-Linked Unskimmed Habitat
This set-up maximizes niche habitats, increases biodiversity and spatial heterogeneity, minimizes maintenance, and is an accurate mimic of natural interrelated communities. refugium surge Seagrass area receives passive overflow from reef and acts as a settling area for detritus which mixed substrate feeds the grasses
reef system Sea Grass System
deep coarse sand substrate deep very fine sand substrate
Reversereverse daylight daylight
optional reverse daylight Intertidal sump
no substrate, rock rubble, some exposed to air 1200 l main reef aquarium, unskimmed, multi-linked habitat (1998)
12-25 cm sand bed, No plenum 1200 l main reef aquarium, unskimmed, multi-linked habitat (1999) 1200 l main reef aquarium, unskimmed, multi-linked habitat (1999)
Coral tips exposed to air during each surge 1200 l main reef aquarium, unskimmed, multi-linked habitat (1999) 2004 2004 2006 2006 300 l seagrass tank, multi-linked habitat, unskimmed (2000)
Seagrasses present: Thallasia testudinum, Halodule wrightii, Syringodium filiforme
Small “patch-reef”
12-18 cm very fine grain sand bed, no plenum, some carbonate muds 300 l seagrass tank, multi-linked habitat, unskimmed
1 month after “planting” note Penicillus and Avrainvillea, common to seagrass areas 300 l seagrass tank, multi-linked habitat, unskimmed
Note lack of epiphytic growth on Thallasia blades.
Shed blades are not removed from the system but are allowed to fall to bottom and decompose 300 l seagrass tank, multi-linked habitat, unskimmed
Note natural positioning of Catalaphyllia jardinei in silty, lagoon-like setting 2006 2006 2007 2007 Quantitative Comparisons and Summary
System temperature salinity pH calcium alkalinity NO3 PO4 O2 surf. light water (oC) (ppt) (mg/l) (meq/l) (mg/l) (mg/l) (% sat.) (µEm2s-1) Coral reef 27.6 34.8 •8 .20 •420 2.2-2.4 .0155 .0124 •2000 Commerci 26.03 35.27 8.053 416 na <.04526 .0222 95.9 1900 11.277 al ATS Personal 28.9 34 8.10 420 3.52 <.50 <.05 •88 •600 .25 ATS Jaubert 8.24 520 Na .013 Personal 27.8 35 8.38 460 4.2 .097 .0480 •93 .0 •900 .05 Jaubert Linked 28.9 35.5 8.20 435 3.4 .074 .026 •98 .0 •1650 .25 habitat Personal 26.7 34 8.40 450 4.2 4-10 .20-.27 na •1000 .10 Berlin Supplements/Additive based methods “Miracle” Muds Probiotics Zeovit Things I Know
1. You don’t need a skimmer (but good to have for emergencies) 2. You don’t need to do water changes 3. There is nothing you need to buy at a store except salt, livestock (although some equipment, some food, and tanks are okay) 4. You can grow corals in a glass of water with an airstone if you want. 5. There are a thousand ways to grow coral and keep fish alive. 6. Less is more – and infinitely more impressive. 7. Reproduction is the real future and goal of reefkeeping 8. Food is the major limitation of the hobby’s success 9. None of these points are necessarily “ideal” 10. Don’t do anything like I do it (unless you want to). Hypothetical Ideal?
6 x 1000w 6500K HQI bulbs
Surge tank 3200L 40L Seawater reef reservoir
Cultures 100,000L 30g/d
Seagrass and/or Lagoon habitat 40,000L Issues with Closed Systems
1. The problem with scale 2. The problem with diversity 3. The problem with biomass:water volume 4. The problem with organism choice 5. The problem with replicating natural processes Reef Designs
Changing (slowly) from mixed species “garden reefs” to somewhat more specialized habitats
Advantages: more normal behavioral and biological interactions = more reproduction, better health, better growth, less mortality The Problem of Scale
Options
1) recreate an entire “reef-in-a-box” 2) recreate a niche or microniche 3) recreate a population (aquaculture) Example of Biomass/Habitat The Problem with Diversity: Stocking Order
The Problem with Diversity: Deep Sand Beds
Advantages: Highly effective nutrient decomposition/remineralization Increased biodiversity and spatial heterogeneity Habitat for sand dwelling species
Disadvantanges High oxygen consumption Can be mismanaged (remotes are good)
Myths Sandbeds are not a nutrient sink
Anaerobia and H2S are rarely problematic Stratification of sand layers - 160l Jaubert tank with plenum
aerobic surface layer hypoxic layer Cyanobacteria and reductive areas in sand bed 80l attached refugium, unskimmed, no plenum
cyanobacteria reductive areas Deep Sand Bed, Lagoon system, Smithsonian ATS Microcosm (Adey and Loveland 1998)
polychaete and amphipod burrows
Reductive areas and heavy pockets of detritus The Problem with Diversity and The Problem with Food: Refugiums
Areas within or attached to a main reef which provide a habitat free of predation for the growth and reproduction of pelagic and demersal, and thigmotactic phytoplankton and zooplankton-type organisms. 160 l ATS tank, showing “drop-in” refugium (1998)
refugium 2008 Ideal Refugium
1. Should be as large as possible 2. Should be fed (including phytoplankton) 3. Should have low turnover 4. Should passively flow into tank 5. Should contain high spatial heterogeneity (rubble, sand) for demersal zooplankton 6. Should contain turf species more than macroalgae 7. Should actively add or culture copepods, rotifers, Artemia The Problems with Diversity: Live rock on a Reef My 15-year old live rock…..no “old tank syndrome” here - intermediate disturbance works in the wild…tanks too? The Problem with Diversity: Competition and Closed Systems
Reduce stocking density, allow for growth Know competitive strategies, avoid incompatible species Activated carbon, clays and water changes for secondary metabolites The REALLY Important Things
Light (available, but amounts are uncertain)
Water motion (available, but amounts are uncertain)
Water Quality (available)
Food (improving, but still lacking) Lighting and Photosynthesis
- Zooxanthellae provide photosynthate - Photosynthate is mostly carbon-rich “junk food,” mostly lost as mucus -In high light, photosynthesis can provide up to160% of carbon, but corals are nitrogen limited. - Shade-adapted corals typically meet 60-80% of carbon, and are carbon limited in low light and/or low water flow.
- However, Pmax is not hard to achieve Photosynthetic Saturation - varies across taxa - A LOT - plus ID problems - no correlation between polyp size and saturation level - soft corals may be higher than stonies - any more needs to be “managed” - photoinhibition possible
Spectrum versus irradiance and your bulbs - zooxanthellae strain variations - pigmentation differences - zoox + animal - photoacclimation/adaptation - highly capable - photons are photons
Coral Coloration
Fluorescing protein (Dove et al. 2001) Coral pigmentation
-Coral color in zooxanthellate corals due to fluorescing and non-fluorescing proteins (>300, RGB genes) - Zooxanthellae are brown and can influence color - Function is unclear and variable (light, genetics, food?)
Ideal Lighting
1. Dawn and dusk period – 0-1600-0 PAR within 2 hours
2. Highly variable PAR throughout day (prevents photodamage)
3. Seasonally variable photoperiod – reproduction/rhythms
4. Moonlight – varies with lunar cycle (0-10 PAR)
5. Majority of light 6500K-10000K (reflector up to 10X more, glitter lines up to 500X more)
6. Can add blue/UV for fluorescence aesthetics
7. USE A PAR METER Water Motion Water Flow Affects: • Light • Nutrition • Water quality • Direct and indirect species effects • Growth forms
Additionally affects: photosynthesis gas exchange (water + animals) respiration health (disease + bleaching) tissue growth calcification rates larval dispersal sedimentation waste removal fragmentation Flow characterization
Low flow 1 - 5 cm/sec Medium flow 6 - 20 cm/sec High flow 21-50 cm/sec Very high flow>50 cm/sec
Flux rate measured across a 1 meter strip of Davies Reef, Australia: 12,000 cubic meters/day, or about 500 cubic meters/hour!! Average Reef Flow Rates
Reef Area Typical Flow speed Reef crest, fast currents, 7 Ğ 100 cm/sec wave surge Lagoon 1 - 16 cm/sec Deep fore-reef (deeper than <5 cm/sec 25 m) unidirectional Mid- to deep fore-reef (15- 5 Ğ 7 cm/sec, or less 25 m) unidirectional Shallow fore-reef 9 Ğ 16 cm/sec Storms 7 meters/sec Best Water Flow Devices
Propeller powerheads (wide flow) - high volume, low velocity Wavebox Dump buckets Surge tanks Controllable wide-flow (Vortech) 2008 Ideal Water Flow
1. Turbulent flow decreases boundary layers 2. Random flow eliminates “dead spots” but some dead spots fine 3. Low power, low turnover pumps with flow generated in tank - big pumps with lots of high velocity outputs NOT ideal 4. Mass flux, low velocity is ideal 5. 10-30cm/sec is ideal for most corals/reef habitats 6. Combination of methods often works best Food
Corals are polytrophic • They use light – for carbon • They consume zooplankton, detritus (and a few eat phytoplankton) • They farm, capture, and utilize bacteria • They absorb dissolved nutrients Composition and Amounts of Zooplankton by Time of Day
Type day (mg/m-3) night (mg/m-3) Copepods 174 1574 Appendicularians 4 34 Chaetognaths 2 70 Amphipods 0 26 Ostracods 2.5 138 Decapods .7 43 Veligers 15 382 Foraminferans 4 10 Fish larvae 13 70 Mysids 6 701 Crab Zoe 0 237 Polychaetes 4 38 Total Haloplankton/Meroplankton 130 2346 Total Microplankton 11 181 (zooflagellates, ciliates, nauplii) Some Levels of Zooplankton in Reef Waters
- .5 kg m-1 d-1 of waterborne plankton over a reef crest1
- Copepod levels from 500,000 m-3 to 1,500,000 m-3, with swarms from 1-2m2 to 30m3
Organism type density of cells/ml water Bacteria 106 Phototropic picoplankton and nanop lankton 104 Nanoplanktonic flagellates 103 Microphy toplankton 103 Viral particles 108 “Small-Polyped Corals Don’t Need To Be Fed”
Number of zooplankton captured by equivalent biomass of coral 100 polyps of M. cavernosa 9000 polyps of M. mirabilis
Captures per 20 min.
M. cavernosa
M. mirabilis
0 500 1000 ..but Acropora are different
Energy budget for Acropora palmata Trophic Levels - Averages Nutritional experiment in Rotterdam
30
25
20 control
]
2 600 nauplii L-1 15 1800 nauplii L-1 3750 nauplii L-1 Size [mm 10
5
0 Start 0,5 1 1,5 2 2,5 3 3,5 4 4,5 5 Months
Same findings at GBRMPA, Lisbon, Italy, Oceanopolis (2006-7) Ideal Food Solutions
1. Large refugium 2. Addition of live foods (small), diverse foods 3. Retention of waterborne particulate matter (skim less) 4. Constant feeding apparatus (wine chiller or small refrigerator, stir plate, dosing pump) The Problem with Pests: Quarantine Tanks
-new widespread problem
-an issue of “trading frags”
3-4 weeks, magnification
Treatment tanks Ideal Quarantine Tank
Small aquarium with live rock and aged seawater
Light – 200 PAR
Strong turbulent water flow with skimming (ozone)
Water changes with tank water from display Water Quality
Four Methods to Address Water Quality
1.Bacteria (carbon – fast; nitrogen/phosphorus – slow) 2.Algae (nitrogen/phosphorus) 3.Export - skimmers (primarily carbon and particulates – food) - biomass removal (corals, algae, fish) 4.Water changes
Water Quality - additions
Only four things needed to add to tanks: 1.Calcium 2.Carbonate (alkalinity) 3.Magnesium (occassional) 4.Food
Anything else unknown, unmeasurable, untested, unwanted, unneeded Our tanks are not like seawater regardless of salt mix or water- change schedule
Bacterial Symbioses: Prey, Pathogens or Pals?
Corals, sponges, and other invertebrates harbor species- or location-specific microbial surface biota
Possible roles: - antibiotic - metabolic homeostasis - nutrient acquisition - food
Also may play a role in coral disease - “microbiota shift diseases” - equilibrium shifts - evidence from sponge and coral studies The coral “holobiont”
Coral, zooxanthellae, bacteria, symbionts, and environment - a lesson to think about in aquaria
Carbon Dosing (sugar, ethanol)
• increases bacteria (??) • forces C:N:P Redfield ratio changes (106:16:1) • carbon linked to coral disease (microbiota shift) Algae Issues “Bottom Down” or “Top Up” ???
Cyanobacteria - low correlation with nutrients - high correlation with water flow - significant correlation with grazing - high correlation with season
Filamentous algae - mixed correlation with nutrients - high correlation with grazing
Fleshy macroalgae - high correlation with grazing and palatability Ideal Water Quality
1. Keep calcium, alkalinity, magnesium high (alkalinity higher than reef (historically higher) 1. Oxygen is critical – tank design, water flow, reverse lighting 2. Alkalinity and oxygen take care of pH and redox 3. Salinity – 35-37ppt 4. Water changes optional/as needed 5. Keep tank nitrogen limited (Redfield ratio, reef limit) - Skimming removes C and some P (coral mucus) - Algae removes N and P 6. Herbivores remove algae (rarely are nutrients the problem – they are just fuel) 7. Water flow removes cyanobacteria Conclusions
My philosophy of reefkeeping: 1. Plan the habitat first 2. Know the animals before you buy them 3. Do whatever it takes to keep tank healthy (no dogma) 4. Always have a quarantine tank 5. Be patient and also be prepared to act quickly 6. Spend more time watching your tank than playing with the toys and products Thank You!
Whale shark at the Flower Garden Banks, 2003