This document discusses how physical factors like sea level rise, sediment particle size, beach slope, and wave exposure affect benthic invertebrate assemblages in estuaries. It finds that the abundance, biomass, and oxygen consumption of intertidal macrofauna and meiofauna are significantly impacted by interactions among these physical factors. Specifically, mud flats have lower wave exposure and finer sediments leading to higher macrofauna biomass, while sandy shores have higher wave exposure and coarser sediments resulting in lower biomass. Sea level rise is expected to make estuaries less diverse and productive by reducing these metrics.

1. Sea level rise on estuarine slope,
sediment particle size and wave
exposure. How they affect benthic
invertebrates?
LIMARIE J. REYES TORRES
CIAM 6117
LORETTA ROBERSON, PH.D.
UNIVERSITY OF PUERTO RICO RIO PIEDRAS CAMPUS

2. http://www2.southeastern.edu/orgs/oilspill/ima
ges/marsh_salinity.jpg

3. Why protect them?
 Transitional zones that encompass a wide
variety of environments.
 Ecologically
 Are among the most productive natural
environments in the world.
 Sustain organisms in many of their life stages,
serve as migration routes, and are havens for
threatened and endangered species.
 Associated wetlands filter pollutants, dissipate
floodwaters, and prevent land erosion.
 Economically
 Support major fisheries, shipping, and tourism.
Ohrel, R. L., & Register Kathleen M. (2006).
http://marlimillerphoto.com/images/Dep-59.jpg

4. Source: http://ian.umces.edu/loicz/estuaries.png

5. Sea level rise a serious problem for
estuaries
 Global warming is likely to cause the
present rate of sea level rise to
increase, posing additional concerns
for coastal and estuarine
environments.
 Among the serious issues relating to
climate change are:
 Increased flood risks
 Threats to the maintenance of coastal
hard defenses
 Coastal squeeze
Fujii, T. (2012).

6. Physical factors on benthic invertebrate assemblages
 Understanding the impacts of the physical
constraints imposed by sea level rise on benthic
assemblages is important for evaluating and
managing threats to future ecosystem service
provision.
 Changes in these physical estuary characteristics
are likely to have an impact on:
 benthic invertebrate biomass
 benthic invertebrate body size distribution
 ecosystem processes
 The nature of these impacts is likely to be
determined by the interactions among the
physical constraints of:
 particle size
 beach slope
 wave exposure
Yamanaka T, Raffaelli D, White PCL (2013).
http://ecologybehavior.weebly.com/uploads/8/7/2/6/8726686/3804058.gif?398

7. Benthic macrofauna and meiofauna
 Macrofauna
 Invertebrates that live on or in sediment, or attached
to hard substrates
 move freely through sediments
 change the structure and chemistry of the microenvironment
by burrowing activity
 1 mm or bigger
 Ex. Annelid worms, bivalves, gastropods, crustaceans,
amphipods
(Virginia Institute of Marine Science)
 Meiofauna
 Multi cellular organisms
 Live interstitially among sediment particles
 Entirely aquatic
 Smaller than 1 mm
(International association of meiobenthologists)
http://www.swt.org.za/images/macrofauna.jpg
Ciliata Nematoda Turbellaria
http://www.marbef.org/projects/Manuela/photo_gallery.php?album=18

8. The intertidal zone
of an estuary
 Exposed to the air at low tide and
submerged at high tide.
 Drastic changes in
 Water level
 Salinity
 Temperatures
 Organisms in the intertidal zone are
adapted to harsh extremes.
 Different types of habitats,
including steep rocky cliffs, sandy
shores or vast mudflats.
Ocean and Coastal Resource Management -NOAA (2008).
http://www.nzdl.org/gsdl/collect/envl/archives/HASH0192.dir/p045.gif
http://ecologybehavior.weebly.com/uploads/8/7/2/6/8726686/3804058.gif?398

9.  Depending on sediment grain size
 Distribution along shoreline is primarily due to relative strength of
prevailing water currents
 Mixed sand-mud flats can occur between the two systems but this
zonation may be modified by the presence of tidal creeks and
sediment flux (Dineen, J. 2015).
Intertidal zones: Mudflats and sandy beaches
https://sites.google.com/site/wvugeol616advancedsed/_/rsrc/142893223
5884/home/tidal-systems/tidal%20facies.JPG

10.  Low wave exposure (low energy)
 Flatter (gentle) slopes
 Finer sediment particle size
 Higher stability
 Poorly sorted sediments
 Fine muds and silts
 provide a large surface area for the
accumulation of organic matter and
microbial processes
 Anoxic areas below the surface because of
higher oxygen uptake
 Macrofauna
 High number of species (high species richness)
 High abundance
 High biomass
 High oxygen consumption
 E.g. deposit and filter feeding taxa
Mud flats
Fujii, T. (2012); Yamanaka T, Raffaelli D, White PCL (2013).
http://www.jochemnet.de/fiu/Mudflat_Comm.gif
http://www.holland.com/upload_mm/a/5/2/14466_fullimage_wadden_wadlopen_closeup_560x350_tcm4
22-138051_560x350.jpg

11. Estuarine sandy shores
 High wave exposure (high energy)
 Steeper slopes
 Coarser sediment particle size
 Lower stability
 Macrofauna
 Low abundance
 Low biomass- low productivity
 Low oxygen consumption
Fujii, T. (2012); Yamanaka T, Raffaelli D, White PCL (2013).
http://footage.framepool.com/shotimg/qf/792292702-cape-bianco-
estuary-steep-coast-sicily.jpg

12. Estuarine intertidal macrobenthic biomass and
key environmental factor
Fujii, T. (2012).

13. Slope, particle size and wave exposure
on Meiofauanal abundance
Yamanaka T, Raffaelli D, White PCL (2013).

14. Implications for Estuarine Physical Elements
Fujii, T. (2012).

15. Conclusion
 Abundance, biomass and oxygen consumption of intertidal macrofauna
and meiofauna are affected significantly by interactions among:
 sediment particle size
 beach slope
 wave exposure
 This interaction is probably as important, if not more so, for predicting
changes in beach fauna than the effect of any single physical factor.
 If beach physical factors change as predicted, then sea-level rise will make
estuarine intertidal areas less diverse and less productive, through declines
in abundance, biomass, and community metabolism as well as through the
loss of area due to coastal squeeze.
 Sea-level rise is likely to lead to changes in ecosystem structure with
generally negative impacts on ecosystem functions and ecosystem
services.
Yamanaka T, Raffaelli D, White PCL (2013).

16. Discussion
 Is it possible to minimize, stop or reverse the harms we have caused on
estuaries? How?
 What can you do as an individual to address this issue?
 Should management decisions regarding estuaries have more of an ecological
or economical approach? Why?
 From an economic viewpoint, why should we care about estuaries?
 To what extent should economic activity dictate the outcome of estuaries?

17. References
 (2011). Programa del Estuario de la Bahía de San Juan. http://estuario.org/
 Dineen, J. (2015). Smithsonian Marine Station at Fort Pierce. http://www.sms.si.edu/irlspec/Tidal_Flats.htm
 Fujii, T. (2012). Climate Change, Sea-Level Rise and Implications for Coastal and Estuarine Shoreline Management with
Particular Reference to the Ecology of Intertidal Benthic Macrofauna in NW Europe. Biology 1, 597-616.
 Ohrel, R. L., & Register Kathleen M. (2006). Volunteer Estuary Monitoring A Methods Manual. EPA and Ocean Conservancy.
 Shallow Water Communities – Macrofauna. Virginia Institute of Marine Science.
http://web.vims.edu/bio/shallowwater/benthic_community/macrofauna.html
 Yamanaka T, Raffaelli D, White PCL (2013). Non-Linear Interactions Determine the Impact of Sea-Level Rise on Estuarine
Benthic Biodiversity and Ecosystem Processes. PLoS ONE 8(7): e68160.
 http://ian.umces.edu/loicz/estuaries.png
 http://www.meiofauna.org/phyla34.html
 http://www.theonlinefisherman.com/images/00_reel_news/2014/11/17/kill-1.jpg
 http://www.umces.edu/sites/default/files/images/ian_bioscience_seagrass.jpg
 http://ed101.bu.edu/StudentDoc/Archives/ED101fa10/clcupp/compaction.html
 http://www.mbari.org/news/homepage/2010/mcclain-macrofauna.jpg
 http://www.swt.org.za/images/macrofauna.jpg