Coral reefs are in trouble; they are being stressed on a global scale by diverse factors many of which are related to human stressors which are now

Size: px

Start display at page:

Download "Coral reefs are in trouble; they are being stressed on a global scale by diverse factors many of which are related to human stressors which are now"

Griselda Owens
5 years ago
Views:

1 Coral reefs are in trouble; they are being stressed on a global scale by diverse factors many of which are related to human stressors which are now compounded by environmental change. Today increasing awareness has led to a more robust, coordinated policy framework triggered by a transformative events; the wreck of the Argo Merchant in 1976 and Exxon Valdez in Here we discuss four events that took place in Puerto Rico before that policy framework matured to become a robust mechanism for dealing with vessel groundings in PR waters 1

2 Ensuring our ecosystems have the capacity to persist especially in the context of complexity and irreducible uncertainty 2

3 3

4 4

5 M/T Spervik was a 537 Dirty Tanker Fully Loaded with Crude Oil Sailing from Curacao to New York Built in 1955 The full load draft was 30 ; b~4 million gallons Only slightly smaller of M/T Ocean Eagle (575 and Zoe (605 Event 5 year before Ocean Eagle, ten before Zoe and Argo Ran aground inside Playa de Pajaros, rode over outer reef Did not break up ran up Spur and Groove reef framework Loaded but hull did not break-up, became aligned with reef Bow hard aground but 2/3 and stern nestled? Kinetic energy dissipated by coral crushing work 5

6 Vessel was lightened oil removed using barges Some oil is visible in newspaper photo as well as booms deployed. Offloading assisted by weather? Unusual calm may have prevaied. Winter months characterizedby strong swell. Refloating required most powerful Atlantic tug at the time the Smit Elbe Vessel Dry docked in England >10 month, sold and re named Was scrapped in1973 Event poorly documented; Pre-EQB, DNR Unusual reef pre-strssing helped favorable outcome? 6

7 Stranded about 1,000 NE of Cueva de la Escalera 7

8 The 12/12/63 photo earlier shows an unusually moist Mona Some 80 days before the grounding Hurricane Edith passed through the area. The storm surge reached ~8 and a strong swell was registered. At La Parguera the storm caused significant destruction of Acropora stands to a depth of 30 The storm may have pre-stressed the reef making it more vulnerable to crushing and less likely to puncture the hull Technically the grounding became a stranding. This favorable condition must have been complemented by relatively calm conditions during cargo offloading and vessel extraction from reef. Winter months are often characterized by swell normally 8

9 Scar at Spur and Groove Spervik stranding site 9

10 Fronted by an outer and inner spur and groove structure. The inner lagoon is shallow < 7 fathoms,with reef reaching mean sea level The inner reef thalus is at about The outer reef >7 fathoms defined by breakers. Base at > 7 fathoms Acropora palmata is the dominant coral species at the spurs. Between spurs are sandy Channels some wide The outer reef has gaps with sandy bottom 10

11 M/V Alborada aground at Playa de Pajarov 11

12 Renamed and reflagged as A. Regina ran aground off Playa de Pajaros 15 February

13 13

14 14

15 Ro/Ro 100m LOA, 3658 gt Carried 143 pax and 31 cars Panama Registered Grounded broadside to reef, pounded by 12 swell. Total loss Owners filed for Limitation of liability Petition denied by US District court

16 BB 16

17 Fuel may have been dispersed by lground reef imestone 17

18 Vessel increasingly listed to poty side waves reach boat deck and penetrate interior 18

19 19

20 20

21 Breaking Up A. Regina in situ 21

22 22

23 The ex-brookings APA-140 Built in 1944 as troop carrier 455 LOA Draft 24 ~6800 gt. Designated as nondestructive target for naval Broke its mooring during hurricane Hugo. Stranded above reef Cabras Island Ceiba Partially dismantled, refloated scuttled April 92 23

24 These vessels ~290 gt (200 net) 24

25 Sank off Palominitos Salvaged by Donjon, (1991) now in active service at Cook Inlet in Alaska for oil spill control 25

26 Now owned by CISPRI vessel is an important assest for Cook Inlet Sill Prevention and Response. 26

27 27

28 The Future? Container ships are getting larger sea state can result in large container spills 28

Section ~ 6 : Avoidance of Pollution. This document, and more, is available for download from Martin's Marine Engineering Page -

Section ~ 6 : Avoidance of Pollution Famous Ships List a few famous ships and why are they famous? Infamous Ships Infamous Ships News extract The oil tanker Prestige sank off Spain's NW coast, taking more