Both our oyster size and population in the Chesapeake Bay have been decreasing rapidly — the number of oysters has decreased to about 1 percent of what they were in 1900, and they’re growing physically smaller than they used to. This trend concerns fisheries, foodies, and biologists alike. The fisheries are harvesting smaller and fewer oysters. For the biologists, their concerns aren’t limited to the oysters but rather extend to the ecological services that they provide, such as filtering the water (and thus improving water quality) and creating reefs for other organisms to benefit from. They could also serve as a model for how to deal with other declining species.

The archaeological record holds clues for dealing with this oyster decline. After investigating trash pits along the Chesapeake area and analyzing the size distribution throughout time, they discovered that the oysters were most stable around 3,200 to 400 years ago when Native Americans dominated the land. The oyster population remained relatively constant despite changing climate conditions and rising sea levels; the Native Americans were able to harvest oysters without exerting a continuous heavy pressure on the population.

Archaeologists excavating a trash pit from Native Americans that contains oyster shells

Native Americans tended to fish by hand seasonally and closer to shore, allowing populations in the deeper depths to reproduce without any added human pressures and for depleted populations to strengthen and recover. This contrasts with today’s overharvesting method of dredging along the bottom of the sea (which not only collects the oysters but also harms their environment). However, it should be noted that there were fewer humans to feed, cleaner water conditions with less disease, and a more stable oyster population to start with.

Many are looking to revive or at least combine some of these practices with today’s modern fishing industry in order to become more sustainable. However, we cannot continue to fish at the same production level if we want the oyster population to recover; we have to change our habits. Thus there’s a big push for oyster sanctuaries that halt fishing. This means that there will be fewer oysters available to consume, so we need to decrease our consumption rates.

Hollywood Oyster company harvesting and sorting oysters from the Chesapeake Bay. In order for the oyster population to survive, we need to change our habits.

Even changing our habits — both how often and the style we harvest oysters in — does not mean that oysters will grow to the size and in the quantity that they used to. There’s an uphill battle for the oyster populations to recover with our decreasing water quality and diminishing oyster habitats. The new environment we’ve created in the Chesapeake Bay can never go back to what it was during pre-colonial America, so we need to work with the ever-changing conditions to develop a long-term harvesting plan. If that does not seem plausible, we might need to stop consuming oysters all together and find alternative food sources — taking into account potential long term, irreversible damage we could do to the species.

Sources:

http://insider.si.edu/2016/05/finding-a-more-sustainable-future-for-oysters-in-the-past/

http://www.npr.org/sections/thesalt/2016/07/28/487618421/oyster-archaeology-ancient-trash-holds-clues-to-sustainable-harvesting

Further Reading

http://archive.archaeology.org/1109/features/coast_salish_clam_gardens_salmon.html

http://www.dailypress.com/news/science/dp-nws-chesapeake-bay-indians-20160124-story.html

X-rays are a part of life — you get them when you’re at the dentist, when your bag goes through security at the airport, or when you visit the doctors for a broken bone. But what if I told you that they are now becoming a part of death as well? Scientists have been using a method called X-ray fluorescence (XRF) to analyze Egyptian mummy wrappings to better understand the past.

To first give a sense of what X-rays are, they’re a type of radiation in the electromagnetic spectrum between gamma rays (which are the smallest and the most energy packed) and the visible light spectrum (the light that you and I can see). X-ray fluorescence essentially shoots a beam of X-rays at the sample, which in turn gives off its own unique set of fluorescent X-rays. Those can be used to identify the sample’s elemental composition and  highlight patterns or words that aren’t visible to the naked eye — which is where the mummies come in.

Roman and Greek inscriptions highlighted by XRF

Ancient Egyptians used to layer old, previously-written-on papyrus with plaster to create their mummies, but until just recently, it was impossible to discern what was written on them. It’s like trying to read an article from a newspaper transformed into an aged, multi-layered paper mache object. The liquid in the plaster fades the ink and thins the paper. The layers of paper oriented in all different directions make it nearly impossible to see what was written below the surface. However, XRF (and other X-ray imaging techniques) solves many of these problems. To start, scientists determine the composition of the papyrus to distinguish it from an element in the ink — such as iron or bromine. They can then detect and highlight the ink using these X-ray techniques.

Testing a mummy head at the Lawrence Berkeley Lab to find non-destructive technologies that reveal the hidden writings

One of the advantages of this type of technology is that it’s non-destructive, meaning that this would hopefully deter people from submerging the papyrus in water or resulting to other destructive techniques to try to uncover the message. As of right now, scientists are still perfecting the imaging software, but some preliminary tests have discovered what some people of the ancient past used to write about. Joshua Sosin, a member of this project from Duke University, said, “We have hate mail, the strange diary ramblings of a hypochondriac, contracts and bills of sale.” The more writing we can uncover, the more we can understand the people who had ordinary lives and thus better understand the society they lived in (as opposed to mainly using historical text from influential writers or people publicly displaying their thoughts).

While some scientists are focusing on this technique for mummies, it could be applied to carvings in ancient pottery, discovering the layers of a painted vessel, or relatively dating an object (through elemental analysis using XRF) (see additional readings below). X-ray technologies open up a new method of analyzing artifacts that uncovers information that we previously thought was lost.

Sources:
http://www.sciencealert.com/archaeologists-are-using-x-rays-to-read-inside-mummy-coffins
https://www.wired.com/2016/10/x-rays-revealing-mysterious-writings-mummy-coffins/
https://www.thermofisher.com/us/en/home/industrial/spectroscopy-elemental-isotope-analysis/spectroscopy-elemental-isotope-analysis-learning-center/elemental-analysis-information/xrf-technology.html

Image sources:
http://www.bbc.com/news/science-environment-12820302
https://www.wired.com/2016/10/x-rays-revealing-mysterious-writings-mummy-coffins/

Additional readings:
http://www.bbc.com/news/science-environment-12820302
https://phys.org/news/2016-10-x-rays-uncover-techniques-creation-art.html