Coral Demographic Training
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Coral Demographic Data This portion of the training will review how to measure corals and estimate % old and % recent mortality. The next training section will cover how to distinguish between bleaching and recent mortality and identify whether recent mortality was caused by disease or other impacts. Again, please review the FRRP DRM in-water protocol available on the DRM website under the ‘Surveyor Trainings and Resources’ page before you begin your surveys (http://ocean.floridamarine.org/FRRP/Home/About). Coral Demographic Data • Use the four-letter species codes • A partial list provided on the right side of the datasheet • Collect Width and Height to the nearest centimeter. • Estimate Mortality • Remember, % Old Mortality + % Other Recent Mortality + % Disease Recent Mortality cannot equal > 100%. Measuring Corals Example of size measurements for large coral (left) and small coral (right). Width = Max Diameter Height = Max Perpendicular Relief Note: view is tilted for small coral because its substrate is at an incline (eye and arrow). Measuring Corals When recording Width and Height measurements for adult colonies, be sure that at least one of those measurements is > 4 cm. The minimum measurement for Width and Height is 1cm when entering your data into the online data entry system. Loose Corals If a loose coral is encountered MARE that still has live tissue, it should be recorded on your datasheet. PDIV © K. Marks Some coral species such as Porites divaricata and Manicina areolata are often found on sandy reef habitats unattached to the reef substrate. Knocked Over Corals Note dead area and live area. Height Dead Live Width Distinguishing colony borders can be difficult if…. Parts of the colony have died or broken away. Other colonies of the same or similar species occur close by, or even on, parts of its skeleton. Porites astreoides Orbicella annularis Orbicella faveolata Here an Orbicella franksi has numerous areas of old mortality with overgrowth. What is the extent of the diameter? Where is the lowest and highest point? In the picture to the right, we have multiple species tightly packed together that also have numerous areas of old mortality making them seem like separate colonies. Clues For Distinguishing Colony Borders: • Examine the polyps in the separate areas – are they similar in color, shape and size? • Examine the dead areas (from a side or elevated top view if necessary) – does a common skeleton connect the polyps? Is this one DLAB or two? live dead live ONE! Distinguishing colony borders can be difficult if the colony has naturally occurring old mortality between polyps. Phyllangia americana Estimating % Mortality Colonies that live long enough to become large major reef framework builders tend to accumulate many dead areas. Orbicella faveolata Estimating % Mortality Estimating % DEAD when a coral has only one or two old dead areas is fairly easy. dead dead © J. Lang O. faveolata Estimating % Mortality Estimating % DEAD of a large coral with many dead areas is challenging! TIP: If the colony is very large and/or visibility is poor, you may need to swim around and approximate % DEAD in sub- sections, then total your sub-estimates. Estimating % Mortality When estimating mortality, include ALL parts of the coral that are beneath algae or another animal in % OLD DEAD. The area occupied by the Palythoa is included in the % OLD DEAD estimate of this brain coral. P. strigosa S. siderea S. Millepora Palythoa Chornesky© E. Some additional examples of ‘Old Mortality’ underneath overgrowth. The overgrowth may even be from another coral. Acropora cervicornis S. siderea Encrusting Octocoral S. siderea Standardizing partial mortality estimates 5% 50% 90% 50% 90% Some coral species have a natural growth pattern where they leave behind areas of old mortality as their branches, polyps, or lobes extend outwards. These naturally occurring areas of old mortality should NOT be included in your old mortality estimates. For Orbicella annularis only estimate mortality on the tops of the lobes. Similarly, with Eusmilia fastigiata only estimate mortality where active tissue growth should be occurring. This colony only has recent mortality Orbicella annularis Madracis auretenra & M. decactis Phyllangia americana Eusmilia fastigiata Recent Vs. Old Mortality "Old dead" is defined as any non-living parts of the coral in which the corallite structures are either gone or covered over by organisms that are not easily removed (turf and macroalgae, CCA, invertebrates). Cannot total greater than 99%. 100% Old Mortality – Not recorded. “Recently dead" is defined as any non-living parts of the coral in which the corallite structures are either white and still intact or slightly eroded but identifiable to species. Live Tissue Montastraea cavernosa Recent Mortality Old Mortality Recent Vs. Old Mortality Coral structure is still present in recent mortality Recent Mortality Old Mortality This information is important when documenting disease. Recording disease information will be covered in the next training. 100% Recent Mortality If a coral within your transect has 100% recent mortality OR if it has NO living tissue but has recent mortality between 5% and 100%, please include this coral in your survey. Photo Credit: Bill Goodwin (NOAA) 100% Recent Mortality 25% Recent Mortality 75% Old Mortality 15% + 15% = 30% 70% Recent Mortality Old Mortality Recording Recent Mortality In an effort to better document coral disease and distinguish it from other stressors, recent mortality was divided into recent tissue loss caused by ‘disease’ and recent tissue loss caused by ‘other’ biological or environmental factors. Distinguishing between ‘Other’ and ‘Disease’ recent mortality will be covered in the next training module (LESSON 5 – Coral Condition Training). Juvenile Coral Tally Juvenile coral colonies (<= 4cm) of the target coral families will be tallied along all four transects. , MANG No size measurements or condition information will be recorded for juvenile colonies. If you are not able to identify a juvenile colony in the field, you are encouraged to take photos so that you can consult others after the dive. Please share your photo with Jennifer Stein and others on your team so that we can work together to identify the colony prior to entering the data online. .