Adak Island. He later reported that the 

 plants grew very well. 



Evaluation of Methods 



I have had no success in trans- 

 planting Thalassia and Halodule attached 

 to steel rods. All plants anchored in 

 this manner died within 3 mo. The method 

 does work, however, with eelgrass, and 

 in areas where the sediment is unusually 

 fine, I would suggest that this method 

 be used. The technique using nails as 

 anchors is the easiest of the methods to 

 use when planting by SCUBA diving. The 

 underwater plots in Puget Sound were 4 m 

 (13 ft) deep; installing plugs and sods 

 at that depth was difficult and time 

 consuming. Nails were easily installed, 

 and eelgrass plantings, made using nail 

 anchors, withstand an erosive current 

 flow. The major problem was that the 

 ubiquitous flatfish (mostly English 

 sole, Parophrys vetulus ), which are 

 found in all of the indigenous eelgrass 

 stands in Puget Sound, settle down on 

 top of the plugs and cause them to 

 erode. 



In Izembek Lagoon, clusters of eel- 

 grass were attached to wire mesh in 

 April 1975, and by August 1975, only 

 plants in 2 of 10 plots survived, but 

 these had produced good growth. The use 

 of sods and plugs is better suited for 

 transplanting eelgrass in Alaska. I have 

 had good success with establishment and 

 continued growth of eelgrass using plugs 

 and recommend this method for planting 

 on a massive scale. 



From July 1974 to 1976, I installed 

 78 experimental plots in both the Laguna 

 Madre and Redfish Bay near Port Aransas, 

 Texas (Table 2). Laguna Madre is a high 

 salinity area; Redfish Bay is a normal 

 salinity area. These experimental plots 

 were reduced to approximately 30 plots 

 because of the death of plants on rods 

 and erosion of plants. Of the four meth- 

 ods used in transplanting Thalassia , the 

 fixation to anchors using nails and rods 

 was discontinued, and the two nonanchor- 

 ing methods using sods and plugs were 

 continued. 



I transplanted e^ery 3 mo during a 

 period of 1 yr to determine seasonal 

 differences in the success of trans- 

 plantation. I also found that plant 

 establishment was most successful when 



plantings were made in spring. Spring 

 is the normal active vegetative growth 

 period of indigenous plants. Trans- 

 plantation during the summer, autumn, 

 and winter was successful , but good solid 

 establishment with vegetative shoot pro- 

 duction and rhizome-root growth seems to 

 be delayed until the following spring 

 period (late February, perhaps lasting 

 until May). 



From 26 August 1975 until 16 Feb- 

 ruary 1976, a large dredging project in 

 the channel off Port Aransas released a 

 quantity of unconsolidated silt into the 

 water. Up to 20 cm (7.9 inches) of silt 

 was deposited over a number of experi- 

 mental plots and provided an opportunity 

 to evaluate siltation on plantings. Re- 

 actions of both Halodule and Thalassia 

 to siltation were noted when I dug the 

 plots out. Thalassia had produced new 

 rhizome tips from the upright branches; 

 Halodule had reacted to siltation by 

 angling its rhizome growth upward to 

 stay on top of the sediments. In certain 

 cases, both Thalassia and Halodule were 

 completely covered by the silt, and on 16 

 April 1976, some of these plots were un- 

 covered. Thalassia that had been buried 

 for several months was either dead or 

 showed diminished growth; however, Halo- 

 dule that had been buried showed very 

 vigorous, active vegetative growth with 

 an abundance of new rhizomes, short 

 shoots, and leaves. 



On two different occasions, I trans- 

 ferred Alaskan plants from Izembek La- 

 goon to Puget Sound and used rods as an 

 anchoring device. In 1964 when this was 

 first attempted, the plants lived for 6 

 weeks, putting out new leaves, shoots, 

 rhizomes, and roots, but then suddenly 

 died. This was tried agin in summer, 

 1974, and the plants lived for 9 mo, 

 putting out new shoots, leaves, rhi- 

 zomes, and roots, and then the plants 

 suddenly died. This suggests that we 

 were working with latitudinal ecotypes 

 in eelgrass. McMillan (1979) showed 

 populational differentiation to chilling 

 temperatures along a latitudinal gra- 

 dient from the southern Gulf of Mexico - 

 Caribbean to the northern Gulf for Tha- 

 lassia , Syringodium , and Halodule . 



On 12-13 December 1974, I estab- 

 lished a seagrass garden at Manchester 

 in Puget Sound and installed 14 plots 

 using anchoring methods (rods and 



100 



