mangroves & oil spills...mangrove tree snake (naples, fl) forest floor fauna fiddler crabs ......

Mangroves & Oil SpillsNiger, Africa 1988 spill (dead mangroves):source SciencePhotoLibrary

Increased mutation rates in red mangroves caused by oil and other chemicals that affect chromosome structure:Proffitt, C.E. and S. Travis. 2005. Albino mutation rates in red

mangroves as a bioassay of contamination history in Tampa Bay,

Florida. Wetlands 25:326-334.

Mangroves: Many important uses, functions, and services

Image from The Nature Foundation

• Habitat (above & below water)• Productivity• Protection from storm surge• Reducing erosion of “land”• Sequester pollutants in woody

biomass and indirectly by producing organic soils via root decomposition

World Distribution of Mangroves

Mangrove aerial fauna

Mangrove tree snake (Naples, FL)

Forest floor fauna

Fiddler crabs (Uca spp)

Coffee bean snails (Melampus coffeus)

Prop root and associated aquatics

Subtropical & tropical prop root fauna

More of that

Mangrove tidal creeks

• Important conduits for fauna, productivity export, etc

• But, also avenues for oil and other pollutants to enter deeper into a mangrove forest system

Humans interact with and use mangroves

Some uses more sustainable for the habitat than others(Mangroves converted to shrimp farming)

Mangroves face many problems (habitat loss, pollution, etc)

Today: Oil Spill Focus

Effects

LethalPlant & faunal

mortality

Non-Lethal (slower growth,

reduced production,

MUTATIONS)

Associated Topics

•Clean-up: won’t cover much here

•Restoration: We do a lot of studies on that, but also not covering today

Cleanup of oil in mangroves is difficult

And virtually impossible if it gets into organic sediments (see Burns et al. 2000. Marine Pollution Bulletin 26(5):239-248)

Various techniques have been tried

On to Effects of Oil Spills

Oil coming ashore in mangroves in Panama: 1990s

(some data from this spill later)

Panama: Dead mangrove shoreline following the Galeata spill in the 1980s

Tidal Channel

Live ‘fringe’

Dead strip

Caribbean Panama: Bahia las Minas spill

• About 50,000 barrels of medium-weight crude oil spilled into the Caribbean coast of Panama in the area known as Bahía Las Minas on April 27, 1986.

• the Smithsonian Tropical Research Institute’s Galeta Marine Laboratory received some of the oil. • Fortunately, 15 years of extensive monitoring data and experimental studies,

provided a metric for comparison of effects.

• $4.4M Grant from Minerals Mgmt. Service fueled studies until 1991 (some continued until 1993). PI Jeremy Jackson et al.

Panama: oiled prop roots

Panama: Oiled prop root fauna

Experience Oil in Mangroves !

Panama

TABLE FROM commissionoceanindien.org/fileadmin/resources/Autoroute%20maritime%20IPIECA/IPIECA%20Biological%20impacts%20of%20oil%20pollution%20mangroves%20Vol%204%20IPIECA.pdf

Proceedings 1989 Oil Spill Conference, No. 4479, American Petroleum Institute 447-454.

Florida• The 2010 BP spill: Florida mangroves dodge the bullet

But -- 2012: Cuba begins offshore oil exploration

A big potential problem for south Florida ecosystems –who can say???

Proceedings 1985 Oil Spill Conference, API Publication No. 4385, American Petroleum Institute, Washington, DC, 539-546

Marine Pollution Bulletin 18, 122-124

End of Abstract “

et al.

http://images.library.wisc.edu/EcoNatRes/EFacs/Wetlands/Wetlands16/reference/econatres.wetlands16.hteas.pdf

Some Florida spills & lab experiments

Tampa Bay spill 1993 (oiled shoreline AFTER a cleanup….on the next high tide!)

A collision of three ships in Tampa Bay, Florida, spills 336,000 gallons of fuel oil in 1993.

Tampa Bay: No. 6 fuel oil spill

Tampa Bay (Boca Ciega Bay, War Veterans Park)

Tampa Bay: Oiled Spartina alterniflora just seaward of mangrove fringe -- note Littoraria

Red mangrove seedlings from Tampa Bay Spill: No. 6 fuel oil

Survival of oiled red mangrove propagules collected during No. 6 oil spill in Tampa Bay

Crude Oil effects on mangrove seedlings from Tampa Bay

• Experiment conducted by Donna Devlin & myself while at the Louisiana Environmental Research Center at McNeese State Univ.

• Citation: Devlin, D.J. & C.E. Proffitt 1994. Experimental analysis of the effects of oil on mangrove seedlings and saplings and the mangrove gastropod Melampus coffeus L. pp 3-23. In, C.E. Proffitt & P. Roscigno, eds. Symposium proceedings: Gulf of Mexico and Caribbean oil spills in coastal ecosystems: Assessing effects, natural recovery, and progress in remediation research. MMS 95-0063. Not peer reviewed.

Effects of crude oil in the sediment on red mangrove seedlings: (Proffitt & Devlin)

Red mangrove seedling survival: Crude Oil

Red mangrove: Effects of crude oil on seedlings

Vertical white lines indicate no sig. diff. among means

Summaries of some other studies

http://www.eoearth.org/view/article/159877/

Lab experiment with a SPJC student eventually published in 1995: one-time vs weekly oiling

About 9 weeks

Oiled WeeklyUnoiled Controls (note 2 black mangroves amongst the reds)

Lab Experiment Proffitt et al. 1995. Marine Pollution Bull. 30: 788-793

One time addition of saturation-level oil to sediment VsWeekly addition of small amountsAndNo oil control

STEM GROWTH of Red Mangrove Seedlings

Experimental addition of oil1995. Marine Pollution Bulletin 30: 788-793.

One-time saturation oiling accompanied with hot, outdoor environmental conditions (Florida summer) had greater adverse effects than oil alone (one-time soil saturation or small amounts of oil added weekly)

I’m sure you’re all thinking “When are you going to get to the MUTANTS”?

Mutant Rhizophora

R. apiculata from Palau

R. stylosa (from Yap)

R. mangle (from Florida)

The albino mutation is lethal

• Chlorophyll deficient seedlings can’t photosynthesize

• Seedlings can live up to a year (more usually 6 mo.) on nutritional reserves provided by the maternal tree

Parent trees are heterozygotic

• One allele (a) for albinism, one for ‘normal green’ A, and the normal allele is DOMINANT• AA = normal homozygotic (lives, of course)

• aa = albino mutant (lethal)…BUT you can see and count them on trees because the mother tree is nourishing them!!!!!!!!!!!

• Aa = the heterozygotic condition lives because of the dominant A allele but “carries” & passes on to the next generation the recessive “a” allele.

Recall some basic reproductive biology of the red mangrove

• Viviparous (propagules hanging from trees are germinated seedlings…NOT seed pods!)

Propagules hang on maternal tree for up to 6 + months nourished by the tree (ie., not conducting much if any of their own photosynthesis)

Most Rhizophora mangle self-fertilize• By the time the flower bud opens, the anthers (male parts) have released

pollen and fallen off. Thus, greater chance to self-fertilize than to out-cross

• Remember your high school Mendelian genetics about crosses of a gene that has two alleles. The Punnett Square (below)

A a

A AA Aa

a Aa aa

Male

Female

Albino propagules (yellow or pink on the tree)

Heterozygotic propagules, carriers but look normal green AND CAN SURVIVE to become new trees

Most Rhizophora mangle self-fertilize• By the time the flower bud opens, the anthers (male parts) have released

pollen and fallen off. Thus, greater chance to self-fertilize than to out-cross

• Remember your high school Mendelian genetics about crosses of a gene that has two alleles. The Punnett Square (below)

A a

A AA Aa

a Aa aa

Male

Female

Because of this, a heterozygotic TREE that is 100% selfing will produce GREEN and ALBINO propagules in a 3:1 ratio

Thus (an aside for the biologists out there) deviations from a 3:1 ratio can be used as an estimate of outcrossing

That’s a single tree. For the POPULATION of trees you can count the number of trees producing albino propagules relative to the TOTAL number of reproducing trees.

• Albino mutations occur at some background rate (as in ALL species)

• Oil spills and other “xenobiotic” chemicals that cause chromosomes to break can INCREASE the mutation rate.• Handler & Teas first noticed albinism in red mangroves. 1983. Tasks for

vegetation science Vol. 8: 117-121

• Ed Klekowski and students first used albinism as a bioassay. Klekowski et al. 1994. Marine Pollution Bulletin 28: 346–350.

• Steve Travis and I surveyed albinism statewide in Florida. Proffitt, C.E. and S. Travis. 2005. Albino mutation rates in red mangroves as a bioassay of contamination history in Tampa Bay, Florida. Wetlands 25:326-334.

As part of the USGS Tampa Bay project we found

Mutation rates were higher at most contaminated sites

Not oil in Bishop Harbor,Instead: Phosphate Sludge Pond effluent (repeated spills & releases over many years)

Not all oil spills cause measurable increases in mutation rates:a) Weathered oil may

lose some of the “worse” chemicals because they’re volatile

b) Old spills (one was >25 yrs) may have seen the mutation rate degrade back to near background levels.

That’s about it! Questions?

END