Fish Kill Rooted in Volcanism?

Manila Bulletin, July 24, 2011 | Go to article overview

Fish Kill Rooted in Volcanism?


MANILA, Philippines - Taal Lake, a caldera, has an ecology that is closely linked to its cradling Taal Volcano, one of the 16 volcanoes of the world that erupts every 10 years. We've been studying this lake since 1989. I propose a paradigm to explain the interrelationships leading to the fish kill that began on May 20, 2011. This is based on my integration of my experiences and observations and those of my research team and students over the past 22 years. Recorded eruptionsTaal Volcano has had 33 recorded eruptions since the 15th century. None of these, however, has been associated with fish kills in Taal Lake. The floating fish cage industry reached its peak in 1998. Since then, fish kills, according to the BFAR, have been occurring annually both inside fish cages and in the open waters of the lake. The more remarkable of the fish kills are those in 2000 when 1,700 metric tons (mt) of fish were lost, 2005; 3,700 mt; 2007, 31 mt; and in 2008, 54 mt of milkfish. As of June 6 this year, the May fish kill has been reported to have caused a loss of about 2,000 mt, and counting. Broken down into the affected localities, the losses were approximately 895 mt in Talisay; 375 mt in barangay Sampaloc in Laurel; 268.25 mt, Agoncillo; 150 mt, Mataas na Kahoy; 50 mt, San Nicolas; 20 mt, Lipa; 1.6 mt, Cuenca; 0.565 mt, Sta. Teresita; and 0.235 mt in Alitagtag. Posssible causesSeveral possible causes of the fishkill phenomenon have been forwarded: too low level of oxygen, high level of hydrogen sulfide... could have caused the toxic gas emissions that depleted the lake's oxygen supply, sudden increase in temperature, climate change, decomposing organic matter, and overstocking of the fish cages. The Associated Press reported that the deaths are 'unrelated to the recent signs of restiveness in Taal volcano.' I say, for the recent fishkill, the precipitating factor or trigger of the chain of events leading to it was volcanism coinciding with the start of the wet season in a lake that has apparently exceeded its carrying capacity based on the amount of fish cultured in captivity. Why so?The month of May, 2011, was a time of restiveness of Taal Volcano that kept the Phivolcs on the look-out for a possible eruption. The agency hoisted Alert Level 2 in April. It reported volcanic tremors as frequent as 25 times on May 1-6; 25 on May 7; 7 on May 12; 10 on May 20; and 9 on May 25-27. On the other hand, PAGASA declared May 27 as the official start of the wet season of 2011 after a 'sweltering summer season.' Our research experience in Taal Lake taught us that localized bottom sediments become warmer to hot at the start of the wet season. The same also happens when it suddenly rains on a sunny day. The phenomenon is likened to what happens on land when it rains on a summer day - the wetted ground gives off heat accompanied by escaping water vapor. Our readings led us to discover that in volcanic regions, rain over the watershed sends water percolating through the soil (meteoric water), some of which come in contact with the superheated magma channels deep in the ground. And, like what happens when water is poured over a hot iron rod, the meteoric water is immediately vaporized by the heat released from the magma channel. Heat and steam then move up towards the sediments, causing these to gradually heat up, depending on the amount of heat received. In turn, the sediments transfer heat to the overlying water. Heated water expands, becomes lighter and so rises towards the surface, in the process causing the temperature of the surrounding cool waters to also increase. With time, this temperature increment becomes detectable at the surface in localized lake areas. Fishes in open waters avoid lake areas with temperatures not suitable to their metabolism. Inside fish cages where localized warming occurs, however, fishes are unable to escape and so, they die and float to the surface en masse. Warming causes oxygen gas to easily escape from water, a process called volatilization. …

The rest of this article is only available to active members of Questia

Already a member? Log in now.

Notes for this article

Add a new note
If you are trying to select text to create highlights or citations, remember that you must now click or tap on the first word, and then click or tap on the last word.
One moment ...
Default project is now your active project.
Project items

Items saved from this article

This article has been saved
Highlights (0)
Some of your highlights are legacy items.

Highlights saved before July 30, 2012 will not be displayed on their respective source pages.

You can easily re-create the highlights by opening the book page or article, selecting the text, and clicking “Highlight.”

Citations (0)
Some of your citations are legacy items.

Any citation created before July 30, 2012 will labeled as a “Cited page.” New citations will be saved as cited passages, pages or articles.

We also added the ability to view new citations from your projects or the book or article where you created them.

Notes (0)
Bookmarks (0)

You have no saved items from this article

Project items include:
  • Saved book/article
  • Highlights
  • Quotes/citations
  • Notes
  • Bookmarks
Notes
Cite this article

Cited article

Style
Citations are available only to our active members.
Buy instant access to cite pages or passages in MLA, APA and Chicago citation styles.

(Einhorn, 1992, p. 25)

(Einhorn 25)

1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

Cited article

Fish Kill Rooted in Volcanism?
Settings

Settings

Typeface
Text size Smaller Larger Reset View mode
Search within

Search within this article

Look up

Look up a word

  • Dictionary
  • Thesaurus
Please submit a word or phrase above.
Print this page

Print this page

Why can't I print more than one page at a time?

Help
Full screen

matching results for page

    Questia reader help

    How to highlight and cite specific passages

    1. Click or tap the first word you want to select.
    2. Click or tap the last word you want to select, and you’ll see everything in between get selected.
    3. You’ll then get a menu of options like creating a highlight or a citation from that passage of text.

    OK, got it!

    Cited passage

    Style
    Citations are available only to our active members.
    Buy instant access to cite pages or passages in MLA, APA and Chicago citation styles.

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn, 1992, p. 25).

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn 25)

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences."1

    1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

    Cited passage

    Thanks for trying Questia!

    Please continue trying out our research tools, but please note, full functionality is available only to our active members.

    Your work will be lost once you leave this Web page.

    Buy instant access to save your work.

    Already a member? Log in now.

    Author Advanced search

    Oops!

    An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.