Brine Shrimp Cyst production could be in trouble

[brewmaster15]

I read an interesting article this morning on Brine shrimp while doing some research. Brine shrimp cysts in North America come largely from the Great salt lake in Utah. The brine shrimp release these cysts before their seasonal die off and the cysts are then harvested for the the aquaculture industry. Discus Breeders use these cysts as their primary food source for Discus Fry for instance. Globally Brine shrimp cysts are extremely important in aquaculture. Salinity affects the populations of Brine Shrimp, and salt levels rise, Cyst production drops. Salt levels rise when there is not enough inflow of fresh water, as happens with a drought. At the time of the article writing saline levels were 18 % , in Sept 2022.Predictions are the lake is drying up. Thats pretty serious news for the aquaculture industry and incidentally affects a ton of wildlife.

The article is here,,
https://www.upr.org/utah-news/2022-0...h-brine-shrimp

I was curious on how the lake is doing today so I did some further searching and luckily this year has been better, there was a record snow pack which means more fresh water into the lake. Experts believe that it has bought the area sometime but the problems facing the industry and the lake ecology are still there. The water levels are up 4 feet, but still 6 feet below whats considered healthy by experts.

https://www.usatoday.com/story/news/...e/11736332002/

https://www.sltrib.com/news/2023/05/...ver-emergency/

In other areas, I came across an interesting article on Brine Shrimp production in other parts of the world...

https://www.sciencedirect.com/scienc...52513419304594

Of interest in this article was a reference to some production areas where the brine shrimp stopped producing cysts and switched to reproducing by ovoviviparity (direct production of free-living nauplii)! Thats one way to kill an industry! Apparently this happens when the salt ponds are not in areas with fluctuating seasons. an example of this is the Saltworks like found in Northern Brazil..

Artemia life history is well studied (Abatzopoulos et al., 2002, and references therein). It is characterized by a short generation time, reaching maturity through a series of approximately 15 molts, in less than 20 days. Artemia females present fecundity rates of up to 250 embryos per brood (and up to 20 broods per lifespan). They can reproduce either ovoviviparously (direct production of free-living nauplii) or oviparously (production of encysted dormant embryos). Ovoviviparity is predominantly found in brine shrimp populations under stable environmental conditions. Oviparity, by contrast, is triggered by extreme salinity and temperature, hypoxia, lack of food, short photoperiods, among other stressors (Abatzopoulos et al., 2002).

The relatively stable environmental conditions found in the coastal saltworks of Rio Grande do Norte might partially explain why most of the local brine shrimp populations are currently reproducing ovoviviparously. In such conditions, it would be of selective advantage to produce the majority of offspring ovoviviparously in order to maximize success in intraspecific competition. Conversely, the low percentage of oviparous females currently observed in local saltfields might be interpreted as a sort of insurance retained by these Artemia franciscana populations against unstable or stressful conditions.

Apparently Brine shrimp populations experience rapid genetic changes as well to their environment.

A most impressive feature of the genus Artemia is its high potential for fast genetic changes following colonization or introduction (Abatzopoulos et al., 2002). Rapid evolutionary changes seem to have occurred in natural South American populations of Artemia franciscana, as inferred from the accumulation of novel alleles, apparently as a response to environmental differences (Gajardo et al., 1995). Physiological adaptation of San Francisco Bay (SFB) Artemia after a number of generations to the high temperatures (approximately 40 °C) in Vietnamese salt ponds has been reported (Clegg et al., 2001). Kappas et al. (2004) have also indicated evidence of differentiation of Vietnamese Artemia from the wild (SFB) stock as early as within a year after inoculation. Yet, in spite of the continued accumulated evidence, adaptation in the genus Artemia should be regarded as a complex, multifaceted process involving a variety of environmental and genomic factors. In that domain, molecular genetic approaches (genomics, transcriptomics, proteomics, and metabolomics) will certainly add a new dimension to research (De Vos et al., 2013)

The article mentions cases of this, for instance. In the Great salt lake of utah, Brine shrimp cysts are collected as they float.. over collection may be leading to the Brine shrimp producing cysts that sink!

Empirical evidence that exploitative harvesting might alter productivity and persistence of brine shrimp populations is scarce but expressive. Sura and Belovsky (2016) alerted that current harvesting techniques in Great Salt Lake (Utah, USA) may be selectively harvesting floating cysts and causing the population to shift toward more sinking cysts

and in Brazil

In Brazil, it is plausible to consider that overexploitation of cysts has caused a directional reproductive shift to ovoviviparity (nauplii production) in local brine shrimp populations. Cyst harvesting in Brazilian salterns (for use in local aquaculture) has been a selective pressure on Artemia franciscana for over four decades, and it is likely harvesting has affected brine shrimp populations in multiple ways (population size, phenotypes, fitness components, and genetic variation). The most evident consequence of the current scenario is the stagnation of cyst yields.

In china..

In the Bohai Bay (China), cyst production has been stagnating or even declining in recent years as a result of the reduction of the salt production area, of overharvesting, and of the acidification of salt ponds due to discharge of effluents from bromine extraction plants

Comments welcome and encouraged

[LizStreithorst]

I had heard about the great salt lake drying up. I just didn't think to associate it with the brine shrimp. Thank goodness this year is somewhat better, but the way the climate has been behaving there's no counting on it.

[CliffsDiscus]

My local fish store wanted to know how much I was paying for BBS.The store owner's customer had a difficult time buying BBS in China.
The next time I went to the store I asked the owner he said that the buyer didn't buy from my source but purchase from someone else and was very disappointed because most of the BBS were like sand.